Lossy Compressed Feedback For Multiple Incremental Redundancy Scheme (MIRS)

ABSTRACT

Various embodiments may provide systems and methods for supporting lossy compression of feedback information, such as acknowledgment (ACK) information, negative acknowledgement (NACK) information, etc. Various embodiments may support lossy compression for feedback messages in retransmission systems, such as Hybrid Automatic Repeat Request (HARD) protocols, the Multiple Incremental Redundancy Scheme (MIRS), etc. Various embodiments may support compression of feedback bits using a different compression codebook per symbol or per group of symbols. Various embodiments may support selection of a compression codebook per symbol, or per group of symbols, based at least in part on a probability of successful decoding of each code block in the symbol or group of symbols.

BACKGROUND

Long Term Evolution (LTE), 5G new radio (NR) (5GNR), and other recentlydeveloped communication technologies allow wireless devices tocommunicate information at data rates (e.g., in terms of Gigabits persecond, etc.) that are orders of magnitude greater than what wasavailable just a few years ago.

Today's communication networks are also more secure, resilient tomultipath fading, allow for lower network traffic latencies, providebetter communication efficiencies (e.g., in terms of bits per second perunit of bandwidth used, etc.). These and other recent improvements havefacilitated the emergence of the Internet of Things (JOT), large scaleMachine to Machine (M2M) communication systems, autonomous vehicles, andother technologies that rely on consistent and secure communications.

SUMMARY

Various aspects include systems and methods for supporting lossycompression of feedback information, such as acknowledgment (ACK)information, negative acknowledgement (NACK) information, etc. Variousaspects may support lossy compression for feedback messages inretransmission systems, such as Hybrid Automatic Repeat Request (HARD)protocols, the Multiple Incremental Redundancy Scheme (MIRS), etc.Various aspects may support compression of feedback bits using adifferent compression codebook per feedback group, such as per portionof a symbol, per symbol, or per group of symbols. Various aspects maysupport selection of a compression codebook per feedback group, such asper portion of a symbol, per symbol, or per group of symbols, based atleast in part on a probability of successful decoding of each code blockin the feedback group. Various aspects may include methods forsupporting lossy compression feedback in wireless communicationretransmissions.

Various aspects may include determining first decoding results for anumber of code blocks in a first feedback group received from a sendingdevice, selecting a first compression codebook for use in generating afeedback message for the first decoding results based at least in parton a probability of successful decoding of each code block in the firstfeedback group, generating a first feedback message for the firstdecoding results using the selected first compression codebook, andsending the first feedback message to the sending device.

Some aspects may further include determining second decoding results fora number of code blocks in a second feedback group received from thesending device, selecting a second compression codebook for use ingenerating a feedback message for the second decoding results based atleast in part on a probability of successful decoding of each code blockin the second feedback group, generating a second feedback message forthe second decoding results using the selected second compressioncodebook, and sending the second feedback message to the sending device.In some aspects, the first feedback group may be a first symbol receivedfrom the sending device and the second feedback group may be a secondsymbol received from the sending device.

Some aspects may further include determining a retransmission cyclenumber for each code block in the first feedback group and determiningthe probability of successful decoding of each code block in the firstfeedback group based at least in part on each code block's determinedretransmission cycle number. In some aspects, determining theprobability of successful decoding of each code block in the firstfeedback group based at least in part on each code block's determinedretransmission cycle number may include determining the probability ofsuccessful decoding of each code block in the first feedback group as aprobability value correlated with that code block's retransmission cyclenumber in a pre-defined mapping of retransmission cycle numbers toprobability values. Some aspects may further include receiving from thesending device an indication of a number of code blocks to feedback, anindication of a number of waveforms to be used for feedback, and thepre-defined mapping of retransmission cycle numbers to probabilityvalues, and selecting the first compression codebook for use ingenerating the feedback message for the first decoding results based atleast in part on the probability of successful decoding of each codeblock in the first feedback group may include selecting the firstcompression codebook for use in generating the feedback message for thefirst decoding results based at least in part on the probability ofsuccessful decoding of each code block in the first feedback group, thenumber of code blocks to feedback, and the number of waveforms to beused for feedback. Some aspects may further include receiving anindication of an update to the pre-defined mapping of retransmissioncycle numbers to probability values from the sending device. Someaspects may further include observing a condition of the wirelesscommunication and updating probability values of the pre-defined mappingof retransmission cycle numbers to probability values based at least inpart on an adaptation rule associated with the observed condition of thewireless communication.

In some aspects, the first compression codebook may be selected from agroup of allowed codebooks indicated by the sending device.

In some aspects, the first compression codebook may be signaled to thereceiving device by the sending device.

Some aspects may further include determining a gap-to-capacity number ofunits for a next retransmission and inserting an indication of thegap-to-capacity number of units for the next retransmission in the firstfeedback message.

In some aspects, the first feedback message may include a feedback rankindication.

Various aspects may include generating a mapping of retransmission cyclenumbers to probability values and sending the mapping of retransmissioncycle numbers to probability values a receiving device. In some aspects,the probability values may be based at least in part on a number ofretransmission cycles for a code block. In some aspects, the probabilityvalues may be further based at least in part on one or more of anexistence of frequency spurs, a proximity of a demodulated referencesignal (DMRS), a current estimated signal-to-noise ratio (SNR), and acurrent number of Multiple Input Multiple Output (MIMO).

Some aspects may further include determining a number of code blocks tofeedback, sending an indication of the number of code blocks to feedbackto the receiving device, determining a number of waveforms to be usedfor feedback, and sending an indication of the number of waveforms to beused for feedback to the receiving device.

Some aspects may further include determining an update to the mapping ofretransmission cycle numbers to probability values and sending anindication of the update to the mapping of retransmission cycle numbersto probability values to the receiving device.

Some aspects may further include determining a group of allowedcodebooks for a receiving device and sending an indication of the groupof allowed codebooks to the receiving device.

Some aspects may further include receiving a feedback message from thereceiving device including an indication of a gap-to-capacity number ofunits for a next retransmission, adjusting a retransmission modulationand coding scheme for a next retransmission by the gap-to-capacitynumber of units, and sending the next retransmission to the receivingdevice.

Further aspects may include a wireless device having a processorconfigured to perform one or more operations of any of the methodssummarized above. Further aspects may include processing devices for usein a wireless device configured with processor-executable instructionsto perform operations of any of the methods summarized above. Furtheraspects may include a non-transitory processor-readable storage mediumhaving stored thereon processor-executable instructions configured tocause a processor of a wireless device to perform operations of any ofthe methods summarized above. Further aspects include a wireless devicehaving means for performing functions of any of the methods summarizedabove. Further aspects include a system on chip for use in a wirelessdevice and that includes a processor configured to perform one or moreoperations of any of the methods summarized above.

Further aspects may include a base station having a processor configuredto perform one or more operations of any of the methods summarizedabove. Further aspects may include processing devices for use in a basestation configured with processor-executable instructions to performoperations of any of the methods summarized above. Further aspects mayinclude a non-transitory processor-readable storage medium having storedthereon processor-executable instructions configured to cause aprocessor of a base station to perform operations of any of the methodssummarized above. Further aspects include a base station having meansfor performing functions of any of the methods summarized above. Furtheraspects include a system on chip for use in a base station and thatincludes a processor configured to perform one or more operations of anyof the methods summarized above.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitutepart of this specification, illustrate exemplary embodiments of theclaims, and together with the general description given above and thedetailed description given below, serve to explain the features of theclaims.

FIG. 1 is a system block diagram illustrating an example communicationssystem suitable for implementing various embodiments.

FIG. 2 is a component block diagram illustrating an example computingsystem and wireless modem suitable for implementing various embodiments.

FIG. 3 is a component block diagram illustrating a software architectureincluding a radio protocol stack for the user and control planes inwireless communications suitable for implementing various embodiments.

FIG. 4 is a block diagram of an example portion of a MultipleIncremental Redundancy Scheme (MIRS) slot.

FIG. 5 is a table illustrating example codebooks and resultingdistortions for code block feedback in accordance with variousembodiments.

FIG. 6 is a process flow diagram illustrating a method for supportinglossy compression feedback in wireless communication retransmissions inaccordance with various embodiments.

FIG. 7 is a process flow diagram illustrating a method for supportinglossy compression feedback in wireless communication retransmissions inaccordance with various embodiments.

FIG. 8 is a process flow diagram illustrating a method for supportinglossy compression feedback in wireless communication retransmissions inaccordance with various embodiments.

FIG. 9 is a process flow diagram illustrating a method for supportinglossy compression feedback in wireless communication retransmissions inaccordance with various embodiments.

FIG. 10 is a process flow diagram illustrating a method for supportinglossy compression feedback in wireless communication retransmissions inaccordance with various embodiments.

FIG. 11 is a process flow diagram illustrating a method for supportinglossy compression feedback in wireless communication retransmissions inaccordance with various embodiments.

FIG. 12 is a process flow diagram illustrating a method for supportinglossy compression feedback in wireless communication retransmissions inaccordance with various embodiments.

FIG. 13 is a process flow diagram illustrating a method for supportinglossy compression feedback in wireless communication retransmissions inaccordance with various embodiments.

FIG. 14 is a process flow diagram illustrating a method for supportinglossy compression feedback in wireless communication retransmissions inaccordance with various embodiments.

FIG. 15 is a component block diagram of a network computing devicesuitable for use with various embodiments.

FIG. 16 is a component block diagram of a wireless device suitable foruse with various embodiments.

DETAILED DESCRIPTION

Various embodiments will be described in detail with reference to theaccompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.References made to particular examples and implementations are forillustrative purposes, and are not intended to limit the scope of theclaims.

Various embodiments include systems and methods for supporting lossycompression of feedback information, such as an acknowledgment (ACK)messages and/or or negative acknowledgment (NACK) messages. Variousembodiments may support lossy compression for feedback messages inretransmission systems, such as Hybrid Automatic Repeat Request (HARQ)protocols, the Multiple Incremental Redundancy Scheme (MIRS), etc.Various embodiments may enable reducing the number of bits required tosend feedback information (referred to herein as “feedback bits”),thereby reducing the bandwidth required to transmit feedback informationand reducing the impact on wireless communication system performance inimplementing retransmissions. Some embodiments may support compressionof feedback bits using a different compression codebook per feedbackgroup, such as per portion of a symbol, per symbol, or per group ofsymbols. Some embodiments may support selection of a compressioncodebook per feedback group, such as per portion of a symbol, persymbol, or per group of symbols, based at least in part on a probabilityof successful decoding of each code block in the symbol or group ofsymbols. The selection of a compression codebook based at least in parton probability of successful decoding of code blocks may enable acompression of feedback bits to be adjusted on a per feedback group,such as per portion of a symbol, per symbol, or per group of symbols,basis in response to dynamic changing transmission characteristics, suchas changes in effective coding rates, changes in signal characteristics,etc.

The term “wireless device” is used herein to refer to any one or all ofwireless router devices, wireless appliances, cellular telephones,smartphones, portable computing devices, personal or mobile multi-mediaplayers, laptop computers, tablet computers, smartbooks, ultrabooks,palmtop computers, wireless electronic mail receivers, multimediaInternet-enabled cellular telephones, medical devices and equipment,biometric sensors/devices, wearable devices including smart watches,smart clothing, smart glasses, smart wrist bands, smart jewelry (forexample, smart rings and smart bracelets), entertainment devices (forexample, wireless gaming controllers, music and video players, satelliteradios, etc.), wireless-network enabled Internet of Things (IoT) devicesincluding smart meters/sensors, industrial manufacturing equipment,large and small machinery and appliances for home or enterprise use,wireless communication elements within autonomous and semiautonomousvehicles, wireless devices affixed to or incorporated into variousmobile platforms, global positioning system devices, and similarelectronic devices that include a memory, wireless communicationcomponents and a programmable processor.

The term “sending device” is used herein to refer to a wireless devicethat is sending messages and/or information to a receiving wirelessdevice according to various embodiments. Similarly, the term “receivingdevice” is used herein to refer to a wireless device that is receivingmessages and/or information from a sending wireless device according tovarious embodiments.

The term “system on chip” (SOC) is used herein to refer to a singleintegrated circuit (IC) chip that contains multiple resources orprocessors integrated on a single substrate. A single SOC may containcircuitry for digital, analog, mixed-signal, and radio-frequencyfunctions. A single SOC also may include any number of general purposeor specialized processors (digital signal processors, modem processors,video processors, etc.), memory blocks (such as ROM, RAM, Flash, etc.),and resources (such as timers, voltage regulators, oscillators, etc.).SOCs also may include software for controlling the integrated resourcesand processors, as well as for controlling peripheral devices.

The term “system in a package” (SIP) may be used herein to refer to asingle module or package that contains multiple resources, computationalunits, cores or processors on two or more IC chips, substrates, or SOCs.For example, a SIP may include a single substrate on which multiple ICchips or semiconductor dies are stacked in a vertical configuration.Similarly, the SIP may include one or more multi-chip modules (MCMs) onwhich multiple ICs or semiconductor dies are packaged into a unifyingsubstrate. A SIP also may include multiple independent SOCs coupledtogether via high speed communication circuitry and packaged in closeproximity, such as on a single motherboard or in a single wirelessdevice. The proximity of the SOCs facilitates high speed communicationsand the sharing of memory and resources.

As used herein, the terms “network,” “system,” “wireless network,”“cellular network,” and “wireless communication network” mayinterchangeably refer to a portion or all of a wireless network of acarrier associated with a wireless device and/or subscription on awireless device. The techniques described herein may be used for variouswireless communication networks, such as Code Division Multiple Access(CDMA), time division multiple access (TDMA), FDMA, orthogonal FDMA(OFDMA), single carrier FDMA (SC-FDMA) and other networks. In general,any number of wireless networks may be deployed in a given geographicarea. Each wireless network may support at least one radio accesstechnology, which may operate on one or more frequency or range offrequencies. For example, a CDMA network may implement UniversalTerrestrial Radio Access (UTRA) (including Wideband Code DivisionMultiple Access (WCDMA) standards), CDMA2000 (including IS-2000, IS-95and/or IS-856 standards), etc. In another example, a TDMA network mayimplement GSM Enhanced Data rates for GSM Evolution (EDGE). In anotherexample, an OFDMA network may implement Evolved UTRA (E-UTRA) (includingLTE standards), IEEE 802.11 (WiFi), IEEE 802.16 (WiMAX), IEEE 802.20,Flash-OFDM®, etc. Reference may be made to wireless networks that useLTE standards, and therefore the terms “Evolved Universal TerrestrialRadio Access,” “E-UTRAN” and “eNodeB” may also be used interchangeablyherein to refer to a wireless network. However, such references areprovided merely as examples, and are not intended to exclude wirelessnetworks that use other communication standards. For example, whilevarious Third Generation (3G) systems, Fourth Generation (4G) systems,and Fifth Generation (5G) systems are discussed herein, those systemsare referenced merely as examples and future generation systems (e.g.,sixth generation (6G) or higher systems) may be substituted in variousexamples.

As used herein, the term “RF chain” refers to the components in acommunication device that send, receive, and decode radio frequencysignals. An RF chain typically includes a number of components coupledtogether that transmit RF signals that are referred to as a “transmitchain,” and a number of components coupled together that receive andprocess RF signals that are referred to as a “receive chain.”

The terms “network operator,” “operator,” “mobile network operator,”“carrier,” and “service provider” are used interchangeably herein todescribe a provider of wireless communications services that owns orcontrols elements to sell and deliver communication services to an enduser, and provides necessary provisioning and credentials as policiesimplemented in user device subscriptions.

LTE is a mobile network standard for 4G wireless communication ofhigh-speed data developed by the 3GPP (3rd Generation PartnershipProject) and specified in its Release 8 document series. The 5G system(5GS) is an advanced technology from 4G LTE, and provides a new radioaccess technology (RAT) through the evolution of the existing mobilecommunication network structure. Implementations for 5GS networks arecurrently being adopted that provide new radio (NR) (also referred to as5G) support via NR base stations, such as Next Generation NodeB (gNodeBsor gNBs)). The 5G systems and NR base stations are providing flexibilityin bandwidth scheduling and utilization. Future generation systems(e.g., sixth generation (6G) or higher systems) may provide the same orsimilar flexibility in bandwidth scheduling and utilization.

In LTE and/or 5G (or later generation) systems network devices, such asbase stations, may broadcast packets to wireless devices in a cell. Forease of reference, the term “network device” or “network computingdevice” is used to refer to any of a variety of network elements thatmay perform operations of various embodiments, non-limiting examples ofwhich include a base station, an eNodeB, a gNodeB, an Applicant Function(AF) server, User Plane Function (UPF) server, Operations, PolicyCharging Function (PCF) server, content server, application server, etc.

FIG. 1 illustrates an example of a communications system 100 that issuitable for implementing various embodiments. The communications system100 may be a 5G New Radio (NR) (5GNR) network, or any other suitablenetwork such as a Long Term Evolution (LTE) network. While FIG. 1illustrates a 5GNR network, later generation networks may include thesame or similar elements. Therefore, the reference to a 5GNR network and5GNR network elements in the following descriptions is for illustrativepurposes and is not intended to be limiting.

The communications system 100 may include a heterogeneous networkarchitecture that includes a core network 140 and a variety of mobiledevices (also referred to as user equipment (UE) computing devices)(illustrated as wireless device 120 a-120 e in FIG. 1 ). Thecommunications system 100 may also include a number of base stations(illustrated as the BS 110 a, the BS 110 b, the BS 110 c, and the BS 110d) and other network entities. A base station is an entity thatcommunicates with wireless devices (mobile devices or UE computingdevices), and also may be referred to as an NodeB, a Node B, an LTEevolved nodeB (eNB), an Access point (AP), a radio head, a transmitreceive point (TRP), a New Radio base station (NR BS), a 5G NodeB (NB),a Next Generation NodeB (gNB), or the like. Each base station mayprovide communication coverage for a particular geographic area. In3GPP, the term “cell” can refer to a coverage area of a base station, abase station subsystem serving this coverage area, or a combinationthereof, depending on the context in which the term is used.

A base station 110 a-110 d may provide communication coverage for amacro cell, a pico cell, a femto cell, another type of cell, or acombination thereof. A macro cell may cover a relatively largegeographic area (for example, several kilometers in radius) and mayallow unrestricted Access by mobile devices with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted Access by mobile devices with service subscription. A femtocell may cover a relatively small geographic area (for example, a home)and may allow restricted Access by mobile devices having associationwith the femto cell (for example, mobile devices in a closed subscribergroup (CSG)). A base station for a macro cell may be referred to as amacro BS. A base station for a pico cell may be referred to as a picoBS. A base station for a femto cell may be referred to as a femto BS ora home BS. In the example illustrated in FIG. 1 , a base station 110 amay be a macro BS for a macro cell 102 a, a base station 110 b may be apico BS for a pico cell 102 b, and a base station 110 c may be a femtoBS for a femto cell 102 c. A base station 110 a-110 d may support one ormultiple (for example, three) cells. The terms “eNB”, “base station”,“NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” may be usedinterchangeably herein.

In some examples, a cell may not be stationary, and the geographic areaof the cell may move according to the location of a mobile base station.In some examples, the base stations 110 a-110 d may be interconnected toone another as well as to one or more other base stations or networknodes (not illustrated) in the communications system 100 through varioustypes of backhaul interfaces, such as a direct physical connection, avirtual network, or a combination thereof using any suitable transportnetwork.

The base station 110 a-110 d may communicate with the core network 140over a wired or wireless communication link 126. The wireless device 120a-120 e (UE computing device) may communicate with the base station 110a-110 d over a wireless communication link 122.

The wired communication link 126 may use a variety of wired networks(e.g., Ethernet, TV cable, telephony, fiber optic and other forms ofphysical network connections) that may use one or more wiredcommunication protocols, such as Ethernet, Point-To-Point protocol,High-Level Data Link Control (HDLC), Advanced Data Communication ControlProtocol (ADCCP), and Transmission Control Protocol/Internet Protocol(TCP/IP).

The communications system 100 also may include relay stations (e.g.,relay BS 110 d). A relay station is an entity that can receive atransmission of data from an upstream station (for example, a basestation or a mobile device) and send a transmission of the data to adownstream station (for example, a wireless device or a base station). Arelay station also may be a mobile device that can relay transmissionsfor other wireless devices. In the example illustrated in FIG. 1 , arelay station 110 d may communicate with macro the base station 110 aand the wireless device 120 d in order to facilitate communicationbetween the base station 110 a and the wireless device 120 d. A relaystation also may be referred to as a relay base station, a relay basestation, a relay, etc.

The communications system 100 may be a heterogeneous network thatincludes base stations of different types, for example, macro basestations, pico base stations, femto base stations, relay base stations,etc. These different types of base stations may have different transmitpower levels, different coverage areas, and different impacts oninterference in communications system 100. For example, macro basestations may have a high transmit power level (for example, 5 to 40Watts) whereas pico base stations, femto base stations, and relay basestations may have lower transmit power levels (for example, 0.1 to 2Watts).

A network controller 130 may couple to a set of base stations and mayprovide coordination and Control for these base stations. The networkcontroller 130 may communicate with the base stations via a backhaul.The base stations also may communicate with one another, for example,directly or indirectly via a wireless or wireline backhaul.

The wireless devices (UE computing devices) 120 a, 120 b, 120 c may bedispersed throughout communications system 100, and each wireless devicemay be stationary or mobile. A wireless device also may be referred toas an Access terminal, a UE, a terminal, a mobile station, a subscriberunit, a station, etc.

A macro base station 110 a may communicate with the communicationnetwork 140 over a wired or wireless communication link 126. Thewireless devices 120 a, 120 b, 120 c may communicate with a base station110 a-110 d over a wireless communication link 122.

The wireless communication links 122, 124 may include a plurality ofcarrier signals, frequencies, or frequency bands, each of which mayinclude a plurality of logical channels. The wireless communicationlinks 122 and 124 may utilize one or more radio Access technologies(RATs). Examples of RATs that may be used in a wireless communicationlink include 3GPP LTE, 3G, 4G, 5G (e.g., NR), GSM, Code DivisionMultiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA),Worldwide Interoperability for Microwave Access (WiMAX), Time DivisionMultiple Access (TDMA), and other mobile telephony communicationtechnologies cellular RATs. Further examples of RATs that may be used inone or more of the various wireless communication links 122, 124 withinthe communication system 100 include medium range protocols such asWi-Fi, LTE-U, LTE-Direct, LAA, MuLTEfire, and relatively short rangeRATs such as ZigBee, Bluetooth, and Bluetooth Low Energy (LE).

Certain wireless networks (e.g., LTE) utilize orthogonal frequencydivision multiplexing (OFDM) on the downlink and single-carrierfrequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDMpartition the system bandwidth into multiple (K) orthogonal subcarriers,which are also commonly referred to as tones, bins, etc. Each subcarriermay be modulated with data. In general, modulation symbols are sent inthe frequency domain with OFDM and in the time domain with SC-FDM. Thespacing between adjacent subcarriers may be fixed, and the total numberof subcarriers (K) may be dependent on the system bandwidth. Forexample, the spacing of the subcarriers may be 15 kHz and the minimumresource allocation (called a “resource block”) may be 12 subcarriers(or 180 kHz). Consequently, the nominal Fast File Transfer (FFT) sizemay be equal to 128, 256, 512, 1024 or 2048 for system bandwidth of1.25, 2.5, 5, 10 or 20 megahertz (MHz), respectively. The systembandwidth may also be partitioned into subbands. For example, a subbandmay cover 1.08 MHz (i.e., 6 resource blocks), and there may be 1, 2, 4,8 or 16 subbands for system bandwidth of 1.25, 2.5, 5, 10 or 20 MHz,respectively.

While descriptions of some embodiments may use terminology and examplesassociated with LTE technologies, various embodiments may be applicableto other wireless communications systems, such as a new radio (NR) or 5Gnetwork. NR may utilize OFDM with a cyclic prefix (CP) on the uplink(UL) and downlink (DL) and include support for half-duplex operationusing time division duplex (TDD). A single component carrier bandwidthof 100 MHz may be supported. NR resource blocks may span 12 sub-carrierswith a sub-carrier bandwidth of 75 kHz over a 0.1 ms duration. Eachradio frame may consist of 50 subframes with a length of 10 ms.Consequently, each subframe may have a length of 0.2 ms. Each subframemay indicate a link direction (i.e., DL or UL) for data transmission andthe link direction for each subframe may be dynamically switched. Eachsubframe may include DL/UL data as well as DL/UL Control data.Beamforming may be supported and beam direction may be dynamicallyconfigured. Multiple Input Multiple Output (MIMO) transmissions withprecoding may also be supported. MIMO configurations in the DL maysupport up to eight transmit antennas with multi-layer DL transmissionsup to eight streams and up to two streams per wireless device.Multi-layer transmissions with up to 2 streams per wireless device maybe supported. Aggregation of multiple cells may be supported with up toeight serving cells. Alternatively, NR may support a different airinterface, other than an OFDM-based air interface.

Some mobile devices may be considered machine-type communication (MTC)or evolved or enhanced machine-type communication (eMTC) mobile devices.MTC and eMTC mobile devices include, for example, robots, drones, remotedevices, sensors, meters, monitors, location tags, etc., that maycommunicate with a base station, another device (for example, remotedevice), or some other entity. A wireless node may provide, for example,connectivity for or to a network (for example, a wide area network suchas Internet or a cellular network) via a wired or wireless communicationlink. Some mobile devices may be considered Internet-of-Things (IoT)devices or may be implemented as NB-IoT (narrowband internet of things)devices. A wireless device 120 a-e may be included inside a housing thathouses components of the wireless device, such as processor components,memory components, similar components, or a combination thereof.

In general, any number of communications systems and any number ofwireless networks may be deployed in a given geographic area. Eachcommunications system and wireless network may support a particularradio Access technology (RAT) and may operate on one or morefrequencies. A RAT also may be referred to as a radio technology, an airinterface, etc. A frequency also may be referred to as a carrier, afrequency channel, etc. Each frequency may support a single RAT in agiven geographic area in order to avoid interference betweencommunications systems of different RATs. In some cases, NR or 5G RATnetworks may be deployed.

In some implementations, two or more mobile devices 120 a-e (forexample, illustrated as the wireless device 120 a and the wirelessdevice 120 e) may communicate directly using one or more sidelinkchannels 124 (for example, without using a base station 110 a-110 d asan intermediary to communicate with one another). For example, thewireless devices 120 a-e may communicate using peer-to-peer (P2P)communications, device-to-device (D2D) communications, avehicle-to-everything (V2X) protocol (which may include avehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I)protocol, or similar protocol), a mesh network, or similar networks, orcombinations thereof. In this case, the wireless device 120 a-e mayperform scheduling operations, resource selection operations, as well asother operations described elsewhere herein as being performed by thebase station 110 a-110 d.

Various embodiments may be implemented on a number of single processorand multiprocessor computer systems, including a system-on-chip (SOC) orsystem in a package (SIP). FIG. 2 illustrates an example computingsystem or SIP 200 architecture that may be used in wireless devices (UEcomputing devices) implementing the various embodiments.

With reference to FIGS. 1 and 2 , the illustrated example SIP 200includes a two SOCs 202, 204, a clock 206, and a voltage regulator 208.In some embodiments, the first SOC 202 operate as central processingunit (CPU) of the wireless device that carries out the instructions ofsoftware application programs by performing the arithmetic, logical,Control and input/output (I/O) operations specified by the instructions.In some embodiments, the second SOC 204 may operate as a specializedprocessing unit. For example, the second SOC 204 may operate as aspecialized 5G processing unit responsible for managing high volume,high speed (e.g., 5 Gbps, etc.), and/or very high frequency short wavelength (e.g., 28 GHz mmWave spectrum, etc.) communications.

The first SOC 202 may include a digital signal processor (DSP) 210, amodem processor 212, a graphics processor 214, an application processor216, one or more coprocessors 218 (e.g., vector co-processor) connectedto one or more of the processors, memory 220, custom circuitry 222,system components and resources 224, an interconnection/bus module 226,one or more temperature sensors 230, a thermal Management unit 232, anda thermal power envelope (TPE) component 234. The second SOC 204 mayinclude a 5G modem processor 252, a power Management unit 254, aninterconnection/bus module 264, a plurality of mmWave transceivers 256,memory 258, and various additional processors 260, such as anapplications processor, packet processor, etc.

Each processor 210, 212, 214, 216, 218, 252, 260 may include one or morecores, and each processor/core may perform operations independent of theother processors/cores. For example, the first SOC 202 may include aprocessor that executes a first type of operating system (e.g., FreeBSD,LINUX, OS X, etc.) and a processor that executes a second type ofoperating system (e.g., MICROSOFT WINDOWS 10). In addition, any or allof the processors 210, 212, 214, 216, 218, 252, 260 may be included aspart of a processor cluster architecture (e.g., a synchronous processorcluster architecture, an asynchronous or heterogeneous processor clusterarchitecture, etc.).

The first and second SOC 202, 204 may include various system components,resources and custom circuitry for managing sensor data,analog-to-digital conversions, wireless data transmissions, and forperforming other specialized operations, such as decoding data packetsand processing encoded audio and video signals for rendering in a webbrowser. For example, the system components and resources 224 of thefirst SOC 202 may include power amplifiers, voltage regulators,oscillators, phase-locked loops, peripheral bridges, data controllers,memory controllers, system controllers, Access ports, timers, and othersimilar components used to support the processors and software clientsrunning on a wireless device. The system components and resources 224and/or custom circuitry 222 may also include circuitry to interface withperipheral devices, such as cameras, electronic displays, wirelesscommunication devices, external memory chips, etc.

The first and second SOC 202, 204 may communicate viainterconnection/bus module 250. The various processors 210, 212, 214,216, 218, may be interconnected to one or more memory elements 220,system components and resources 224, and custom circuitry 222, and athermal Management unit 232 via an interconnection/bus module 226.Similarly, the processor 252 may be interconnected to the powerManagement unit 254, the mmWave transceivers 256, memory 258, andvarious additional processors 260 via the interconnection/bus module264. The interconnection/bus module 226, 250, 264 may include an arrayof reconfigurable logic gates and/or implement a bus architecture (e.g.,CoreConnect, AMBA, etc.). Communications may be provided by advancedinterconnects, such as high-performance networks-on chip (NoCs).

The first and/or second SOCs 202, 204 may further include aninput/output module (not illustrated) for communicating with resourcesexternal to the SOC, such as a clock 206 and a voltage regulator 208.Resources external to the SOC (e.g., clock 206, voltage regulator 208)may be shared by two or more of the internal SOC processors/cores.

In addition to the example SIP 200 discussed above, various embodimentsmay be implemented in a wide variety of computing systems, which mayinclude a single processor, multiple processors, multicore processors,or any combination thereof.

FIG. 3 is a component block diagram illustrating a software architecture300 including a radio protocol stack, also referred to as a wirelessprotocol stack, for the user and control planes in wirelesscommunications suitable for implementing any of the various embodiments.With reference to FIGS. 1-3 , the wireless device 320 may implement thesoftware architecture 300 to facilitate communication between a wirelessdevice 320 (e.g., the wireless device 120 a-120 e, 200) and the basestation 350 (e.g., the base station 110 a-d) of a communication system(e.g., 100). In some embodiments, layers in software architecture 300may form logical connections with corresponding layers in software ofthe base station 350. The software architecture 300 may be distributedamong one or more processors (e.g., the processors 212, 214, 216, 218,252, 260). While illustrated with respect to one radio protocol stack(or one wireless protocol stack), in a multi-SIM (subscriber identitymodule) wireless device, the software architecture 300 may includemultiple protocol stacks, each of which may be associated with adifferent SIM (e.g., two protocol stacks associated with two SIMs,respectively, in a dual-SIM wireless communication device). Whiledescribed below with reference to LTE communication layers, the softwarearchitecture 300 may support any of variety of standards and protocolsfor wireless communications, and/or may include additional protocolstacks that support any of variety of standards and protocols wirelesscommunications.

The software architecture 300 may include a Non-Access Stratum (NAS) 302and an Access Stratum (AS) 304. The NAS 302 may include functions andprotocols to support Packet filtering, security management, mobilitycontrol, session management, and traffic and signaling between a SIM(s)of the wireless device and its core network 140. The AS 304 may includefunctions and protocols that support communication between a SIM(s) andentities of supported access networks (e.g., a base station). Inparticular, the AS 304 may include at least three layers (Layer 1, Layer2, and Layer 3), each of which may contain various sub-layers.

In the user and control planes, Layer 1 (L1) of the AS 304 may be aphysical layer (PHY) 306, which may oversee functions that enabletransmission and/or reception over the air interface. Examples of suchphysical layer 306 functions may include cyclic redundancy check (CRC)attachment, coding blocks, scrambling and descrambling, modulation anddemodulation, signal measurements, MIMO, etc. The PHY layer 306 mayinclude various logical channels, including the Physical DownlinkControl Channel (PDCCH) and the Physical Downlink Shared Channel(PDSCH). As an example, the PHY layer 306 may support Channel StateInformation (CSI) measurements and reporting (e.g., Channel QualityIndicator (CQI) measurements and reporting).

In the user and control planes, Layer 2 (L2) of the AS 304 may beresponsible for the link between the wireless device 320 and the basestation 350 over the physical layer 306. In the various embodiments,Layer 2 may include a Media Access Control (MAC) sublayer 308, a RadioLink Control (RLC) sublayer 310, a Packet Data Convergence Protocol(PDCP) 312 sublayer, and a Service Data Adaptation Protocol (SDAP) 317sublayer, each of which form logical connections terminating at the basestation 350.

In the control plane, Layer 3 (L3) of the AS 304 may include a RadioResource Control (RRC) sublayer 3. While not shown, the softwarearchitecture 300 may include additional Layer 3 sublayers, as well asvarious upper layers above Layer 3. In various embodiments, the RRCsublayer 313 may provide functions including broadcasting systeminformation, paging, and establishing and releasing an RRC signalingconnection between the wireless device 320 and the base station 350.

In various embodiments, the SDAP sublayer 317 may provide mappingbetween Quality of Service (QoS) flows and data radio bearers (DRBs). Invarious embodiments, the PDCP sublayer 312 may provide uplink functionsincluding multiplexing between different Radio bearers and logicalchannels, sequence number addition, handover data handling, integrityprotection, ciphering, and header compression. In the downlink, the PDCPsublayer 312 may provide functions that include in-sequence delivery ofdata packets, duplicate data Packet detection, integrity validation,deciphering, and header decompression.

In the uplink, the RLC sublayer 310 may provide segmentation andconcatenation of upper layer data packets, retransmission of lost datapackets, and Automatic Repeat Request (ARQ). In the downlink, while theRLC sublayer 310 functions may include reordering of data packets tocompensate for out-of-order reception, reassembly of upper layer datapackets, and ARQ.

In the uplink, MAC sublayer 308 may provide functions includingmultiplexing between logical and transport channels, random accessprocedure, logical channel priority, and hybrid-ARQ (HARQ) operations.In the downlink, the MAC layer functions may include channel mappingwithin a cell, de-multiplexing, discontinuous reception (DRX), and HARQoperations.

While the software architecture 300 may provide functions to transmitdata through physical media, the software architecture 300 may furtherinclude at least one host layer 314 to provide data transfer services tovarious applications in the wireless device 320. In some embodiments,application-specific functions provided by the at least one host layer314 may provide an interface between the software architecture and thegeneral purpose processor.

In other embodiments, the software architecture 300 may include one ormore higher logical layer (e.g., transport, session, presentation,application, etc.) that provide host layer functions. In someembodiments, the software architecture 300 may include an applicationlayer in which a logical connection terminates at another device (e.g.,end user device, server, etc.). In some embodiments, the softwarearchitecture 300 may further include in the AS 304 a hardware interface316 between the physical layer 306 and the communication hardware (e.g.,one or more radio frequency (RF) transceivers).

Wireless communications between two devices, such as communicationsbetween a base station (e.g., the base station 110 a-110 d, 350) and awireless device (e.g., the wireless device 120 a-120 e, 200, 320), maybe susceptible to interference or other challenges which may interruptor impair the wireless communication. To mitigate such impairments, asending device (e.g., either of the base station or the wireless device)may select a coding scheme based on channel conditions. For clarity, thevarious examples discussed herein may refer to a sending device and areceiving device to indicate the direction of data for a particularexample. When one device, such as the wireless device (e.g., thewireless device 120 a-120 e, 200, 320) is a sending device in a wirelesscommunication, the other device, such as the base station (e.g., thebase station 110 a-110 d, 350) may be the receiving device, and viceversa.

A wireless transmission may be encoded to include error checking andredundancy information that enables a receiving device (e.g., either ofthe base station or the wireless device) to detect and sometimes correcterrors in the wireless transmission. The receiving device may send afeedback message, such as a feedback message including an acknowledgment(ACK) or negative acknowledgment (NACK), to the sending device toindicate whether the data was successfully received. Based on thefeedback message, the sending device may select a different codingscheme, may send a retransmission to assist the receiving device indecoding the data, or both. Some retransmission protocols aim to balancethe benefits of a faster coding scheme with the loss in effective datarate that results from excessive retransmissions.

One example of a retransmission protocol is Hybrid Automatic RepeatRequest (HARD). Devices (e.g., the base station 110 a-110 d, 350 and/orthe wireless device 120 a-120 e, 200, 320) may implement HARQ protocolsto improve throughput, reliability of wireless communication, or both. Asending device may transmit data according to a HARQ protocol. The HARQprotocol may be based on code block encoding that supports errordetection and error correction by the receiving device. The receivingdevice may verify that the code block is properly decoded using errorchecking. When error checking fails, the receiving device may attempterror correction to recover and properly decode the code block. In atraditional HARQ protocol, the receiving device may send feedbackindicating which code blocks were successfully decoded and which codeblocks the receiving device has failed to decode. For each code blockthat the receiving device has failed to decode, the sending device maytransmit a HARQ retransmission that includes additional error correctiondata, the original code block, part of the original code block, or anycombination thereof, in accordance with the established HARQ protocol.

The probability that a code block is successfully decoded may depend ona modulation and coding scheme (MCS) utilized for a HARQ transmission.The MCS may define a coding rate, a bit puncturing rate, a modulationtype, or any combination thereof. Typically, a lower MCS is associatedwith less throughput and higher probability of decoding (i.e., morereliable transmissions and thus fewer retransmissions at the price oflower throughput). In contrast, a higher MCS may be associated withhigher throughput and a lower probability of decoding (i.e., greaterthroughput at the price of less reliable transmission, which may requiremore retransmissions). Some systems may attempt to strike a balancebetween throughput and transmission reliability by selecting an MCS thatresults in the highest effective data rate. The effective data rate of awireless communication medium may be based on the throughput associatedwith successfully decoded transmissions. Failed decoding andretransmissions may lower the effective data rate.

One technique used to improve HARQ protocols may be a MultipleIncremental Redundancy Scheme (MIRS). MIRS may decrease the airtimeassociated with retransmissions such that a threshold quantity ofdecoding failures is acceptable to increase overall throughput. In MIRS,rather than trying to predict channel capacity using the Channel StateInformation Reference Signal (CSR-RS), incremental redundancy (IR) HARQ(IR-HARQ) may be used to find a MCS resulting in the highest effectivedata rate for a current channel.

In MIRS, a first transmission (Tx) may be sent by the sending device(e.g., the base station 110 a-110 d, 350 and/or the wireless device 120a-120 e, 200, 320) at nearly a maximum coding rate or nearly a highestMCS supported by the current channel. For example, in 3GPP the maximumcoding rate may be one and the highest MCS supported may be MCS 28 andas such the first Tx may be sent at MCS 27 and a coding rate slightlyless than one. In this manner, there may be very little redundancy inthe first Tx. If the receiving device (e.g., the base station 110 a-110d, 350 and/or the wireless device 120 a-120 e, 200, 320) successfullydecodes the data of the first Tx, the highest effective data rate forthe current channel is achieved (e.g., MCS 27 if the first Tx issuccessfully decoded when the first Tx is sent at MCS 27).

In MIRS, if the receiving device (e.g., the base station 110 a-110 d,350 and/or the wireless device 120 a-120 e, 200, 320) does notsuccessfully decode the data, a NACK feedback message may be sent fromthe receiving device to the sending device. In response to receiving theNACK feedback message, the sending device (e.g., the base station 110a-110 d, 350 and/or the wireless device 120 a-120 e, 200, 320) mayreduce the coding rate for a next transmission by an increment, such asone MCS level, thereby slightly reducing the coding rate. For example,when the initial MCS was MCS 27 for the first Tx, the MCS for the nextretransmission (Re-Tx) may be reduced to MCS 26. The next Re-Tx may besmall (or thin), having some small additional redundancy not present inthe first Tx. The sending device may transmit the next Re-Tx to thereceiving device. If the receiving device successfully decodes the dataof the Re-Tx, the highest effective data rate for the current channel ispresumed to be achieved (e.g., MCS 26 if the Re-Tx is successfullydecoded when the Re-Tx is sent at MCS 26). In MIRS, if the receivingdevice does not successfully decode the data, another NACK feedbackmessage may be sent from the receiving device to the sending device.

In response to receiving another NACK feedback message, the sendingdevice (e.g., the base station 110 a-110 d, 350 and/or the wirelessdevice 120 a-120 e, 200, 320) may reduce the coding rate again for anext transmission by an increment, such as one MCS level, therebyslightly reducing the coding rate again and may transmit anothersubsequent Re-Tx at the further reduced coding rate. The subsequentRe-Tx may include an additional small amount of redundancy greater thanthat of the previous Re-Tx. The NACK, MCS reduction, and Re-Tx withadditional redundant data cycle may continue as long as NACK feedbackmessages are received from the sending device. Once NACK feedbackmessages are no longer received, the highest effective data rate for thecurrent channel may be achieved at whatever MCS level the successfulRe-Tx occurred. In this manner, a suitable MCS with the necessary amountof redundancy is gradually arrived at by the NACK, MCS reduction, andRe-Tx with additional redundant data cycle. The achievement of thehighest effective data rate for the current channel results in themaximum (or near maximum) capacity code rate for the current channelbeing achieved without requiring a prediction of the channel capacity.Additionally, MIRS enables the effective data rate for transmissions totrack the channel capacity, even if channel capacity is rapidlychanging.

In MIRS, as Re-Tx for each code block (CB) may include a small number ofadditional redundancy bits, a very large number of code blocks (CBs) andtransport blocks (TBs) may be multiplexed in a single transmission timeinterval (TTI). As MIRS may be implemented to provide feedback on a perCB or per small CB group (CBG) basis, a large number of bits may need tobe sent as feedback, such as NACK feedback and/or ACK feedback.Compressing the number of feedback bits may reduce the impact on systemperformance of the MIRS procedure for selecting an appropriate MCS for agiven channel at a given time.

FIG. 4 is a block diagram of an example portion 400 of a MIRS slotillustrating examples of different numbers of code blocks (CBs) pertransport block (TB). With reference to FIGS. 1-4 , while a typical MIRSslot has 14 symbols per slot, FIG. 4 illustrates the portion 400 havingeight different symbols 401, 402, 403, 404, 405, 406, 407, 408. Fivedifferent TBs, TB0, TB1, TB2, TB3, TB4, and TB5 are illustrated and eachTB has its own respective CBs. For example, TB0 has CBs, CB0, CB2, CB3,CB4, CBS, and CB7, TB1 has CBs, CB1, CB3, CB4, CB6, and CB7, TB2 hasCBs, CB2, CB3, CB4, CBS, CB6, and CB7, TB3 has CBs, CB4, CB5, CB6, CB7,TB4 has CBs, CB1, CB3, CB4, and CB7, and TB5 has CBs, CB0, CB1, and CB2.As illustrated in FIG. 4 , different symbols 401-408 may have differentTBs therein.

Each TB in a MIRS slot may be, and typically is, a retransmission(Re-Tx) of a previously failed TB. The number of Re-Txs may vary from TBto TB. For example, TB0 may be in a second Re-Tx cycle, TB1 may be in athird Re-Tx cycle, etc. As more redundant data is added in eachsuccessive Re-Tx cycle in MIRS, the probability of successfully decodingvaries between TBs in different Re-Tx cycles. For example, a TB in itsthird Re-Tx cycle is more likely to pass a cyclic redundancy check (CRC)and be successfully decoded than a TB that is in its second Re-Tx as theTB in the third Re-Tx cycle may have more redundant data than the TB inthe second Re-Tx cycle.

To support faster retransmission cycles, it may be desirable to sendfeedback for a portion of a symbol, every symbol, or every small numberof symbols. Each portion of a symbol, each symbol, or each group ofsymbols, may be a feedback group. Feedback groups may be defined by anumber of CBs such that a feedback group may have a number of CBs lessthan a full a symbol, a number of CBs equal to a full symbol, or anumber of CBs greater than a symbol. Each feedback group, such as eachportion of a symbol, each symbol, or each group of symbols, may becharacterized by a number of CBs in the feedback group to acknowledge(ACK) or negative acknowledge (NACK) and a probability of ACK or NACKper CB. The probability of ACK or NACK per CB may be based at least inpart on the number of Re-Tx cycles of that CB. Additionally oralternatively, the probability of ACK or NACK per CB may be based on oneor more other factors including an existence of spurs and/or notches infrequency and/or time, a proximity of a demodulated reference signal(DMRS), a current estimated signal-to-noise ratio (SNR), a currentnumber of MIMO layers, etc. The probability of ACK or NACK per CB may berepresented by a probability of successful decoding “p”. The probabilityof successful decoding “p” may represent the probability that a CB issuccessfully decoded. The probability of successful decoding “p” may bebased at least in part on one or more factors including, the number ofre-Tx cycles of that CB, an existence of spurs and/or notches infrequency and/or time, a proximity of a DMRS, a current estimated SNR, acurrent number of MIMO layers, etc.

For example, referring to the MIRS slot portion 400, the first symbol401 may include information for seven CBs, CB0 of TB0, CB2 of TB0, CB3of TB0, CB4 of TB0, CB5 of TB0, CB7 of TB0, and CB1 of TB1. Each CB mayhave its own respective probability of successful decoding “p”, suchthat there may be seven probabilities of successful decoding “p” for thefirst symbol 401, specifically p₀-p₆. For example, where the probabilityof successful decoding “p” is governed mainly by the Re-Tx cycles, ifthe CBs of TB0 (CB0, CB2, CB3, CB4, CB5, and CB7) are in their secondRe-Tx cycle their probabilities may all be the same such thatp₀=p₁=p₂=p₃=p₄=p₅=p_(Tx2) where p_(Tx2) is the probability of successfuldecoding “p” associated with a second Re-Tx cycle. Similarly, if the CBof TB (CB1) is in its third Re-Tx cycle its probability may be equal tothe probability of successful decoding “p” associated with a third Re-Txcycle “p_(Tx3)” such that p₆=p_(Tx3).

Similarly, feedback on the fourth symbol 404 may include six CBs, CB6 ofTB2, CB7 of TB2, CB4 of TB3, CB5 of TB3, CB6 of TB3, and CB7 of TB3 withthe CBs of TB2 (CB6 and CB7) having a first probability of successfuldecoding “p_(A)” (e.g., p₀=p₁=p_(A)) and the CBs of TB3 (CB4, CB5, CB6,and CB7) having a second probability of successful decoding “p_(B)”(e.g., p₂=p₃=p₄=p₅=p_(B)).

Various embodiments may include systems and methods for supporting lossycompression of feedback information, such as ACK information, NACKinformation, etc. Various embodiments may support lossy compression forfeedback messages in retransmission systems, such as HARQ protocols,MIRS, etc. Various embodiments may support compression of feedback bitsusing a different compression codebook per feedback group, such as perportion of a symbol, per symbol, or per group of symbols. Variousembodiments may support selection of a compression codebook per feedbackgroup, such as per portion of a symbol, per symbol, or per group ofsymbols, based at least in part on a probability of successful decodingof each code block in the symbol or group of symbols.

In various embodiments, the feedback bits required per feedback group,such as per portion of a symbol, per symbol, or per group of symbols,may be compressed by reducing (e.g., minimizing) an expected penalty ofcompression given a fixed number of bits used to send the feedback. Theexpected penalty of compression given a fixed number of feedback bitsmay be a rate distortion measure “D”. In various embodiments, lossycompression of feedback information may be selected to reduce (e.g.,minimize) the rate distortion measure “D”. The expected penalty may bethe expected number of superfluous CBs the sending device (e.g., thebase station 110 a-110 d, 350 and/or the wireless device 120 a-120 e,200, 320) may retransmit that would not have been retransmitted ifuncompressed (e.g., optimal) feedback bits had been used. The rate ofdistortion measure “D” is therefore the expectation of the excessretransmission the sending device will send to the receiving deviceabove (or on top of) the retransmission that is required.

The rate of distortion measure “D” may be determined according to theequation:

D=E _(n)[d(x _(n) ,g(ƒ(x _(n)))]

where x_(n) is the uncompressed n-th message from a set of |x|=2^(N)messages, and ƒ( ) and g( ) are the compression and decompressionfunctions, respectively. g(ƒ(x_(n))) is the feedback response thesending device will act upon, from set of |g(ƒ(x))|=K messages. [m]represents the m-th bit in the message, x_(n)[m]. g(ƒ(x_(n)))[m] is them-the bit in the original message and reconstructed (compressed)message, respectively, assuming ‘1’ is NACK and ‘0’—is ACK, where m=0, .. . N−1 (for N CBs to send feedback on). Finally:

$d\left( {x_{n},{{g\left( {f\left( x_{n} \right)} \right)} = \left\{ \begin{matrix}{{{\infty{x_{n}\lbrack m\rbrack}} = 1},{{g{\left( {f\left( x_{n} \right)} \right)\lbrack m\rbrack}} = {0{for}{any}{}m}}} \\{\sum\limits_{m}{\left( {{{g\left( {f\left( x_{n} \right)} \right)}\lbrack m\rbrack} - {x_{n}\lbrack m\rbrack}} \right){otherwise}{}}}\end{matrix} \right.}} \right.$

If the compression scheme results in sending Re-Tx for a successfullydecoded CB, the corresponding distortion is increased by one for everysuch CB. If the compression scheme resulted in not sending Re-Tx for afailed CB, the distortion for this case may be defined as infinite andsuch case may be avoided.

In various embodiments, a selected signaling compression codebook to usefor compressing feedback bits may be determined on a per feedback group,such as per portion of a symbol, per symbol, or per group of symbols,basis. A selected signaling compression codebook may be a codebook ofthe available codebooks that reduces (e.g., minimizes) the rate ofdistortion measure “D”. Given a number “N” of CBs to feedback ACK and/orNACK with probabilities of successful decoding “p₀ . . . p_(N-1)” andgiven a fixed number of bits as feedback, or equivalently K number ofwaveforms for feedback where the fixed number of bits as feedback isthen log₂(K) where K<2^(N), the selected signaling compression codebookmay be the codebook of the available codebooks that reduces (e.g.,minimizes) the rate of distortion measure “D.” Said another way, theselected signaling compression codebook may be the codebook of theavailable codebooks resulting a lowest rate of distortion measure “D”from among all the available codebooks.

The selected signaling compression codebook being a codebook of theavailable codebooks that reduces (e.g., minimizes) the rate ofdistortion measure “D” may not be equivalent to standard compressionapproaches, because standard compression approaches minimize the averagesize. In the compression schemes according to the various embodiments,the worst-case feedback per symbol is minimized, not the average size.As various embodiments minimize the worst-case feedback per symbol, thevarious embodiments differ from standard compressions algorithms such asstandard lossless compression algorithms (e.g., Huffman) or standardlossy compression algorithms (e.g., Blahut-Arimoto).

In various embodiments, a different compression codebook may be used perfeedback group, such as per portion of a symbol, per symbol, or pergroup of symbols, based a combination of current the probabilities ofsuccessful decoding “p” for the CBs to be retransmitted. As theprobability of successful decoding “p” may change every Re-Tx cycle,different codebooks may be selected per feedback group, such as perportion of a symbol, per symbol, or per group of symbols, based on thecurrent probabilities of successful decoding “p” for the CBs. In variousembodiments, compression codebook selection may be based at least inpart on a number of CBs to feedback “N”, a number of waveforms to beused for feedback “K”, and probabilities of successful decoding “p₀ . .. p_(N-1)”.

In various embodiments, probabilities of successful decoding “p” may beprobability values pre-provisioned to (i.e., pre-stored in) a device,such as a receiving device (e.g., the base station 110 a-110 d, 350and/or the wireless device 120 a-120 e, 200, 320), sending device (e.g.,the base station 110 a-110 d, 350 and/or the wireless device 120 a-120e, 200, 320), etc. In various embodiments, both the receiving device(e.g., the base station 110 a-110 d, 350 and/or the wireless device 120a-120 e, 200, 320) and the sending device (e.g., the base station 110a-110 d, 350 and/or the wireless device 120 a-120 e, 200, 320) may beconfigured with the same probabilities of successful decoding “p”.

In some embodiments, probabilities of successful decoding “p” may bepre-defined mappings of Re-Tx cycle numbers to probability values storedin a memory of a device, such as the receiving device (e.g., the basestation 110 a-110 d, 350 and/or the wireless device 120 a-120 e, 200,320) and the sending device (e.g., the base station 110 a-110 d, 350and/or the wireless device 120 a-120 e, 200, 320), etc. As an example,the pre-defined mapping may be a look-up table (LUT) correlatingsuccessive Re-Tx cycle numbers with respective probability values.

In some embodiments, the pre-defined mapping of Re-Tx cycle numbers toprobability values may be generated by a sending device. For example, asending device (e.g., the base station 110 a-110 d, 350 and/or thewireless device 120 a-120 e, 200, 320) may determine probabilities ofsuccessful decoding “p” for various different Re-Tx cycles based atleast in part on one or more factors including, the number of the re-Txcycle, an existence of spurs and/or notches in frequency and/or time, aproximity of a DMRS, a current estimated SNR, a current number of MIMOlayers, etc. In some embodiments, the pre-defined mapping of Re-Tx cyclenumbers to probability values may be provided from a sending device to areceiving device. In a non-limiting example, a base station (e.g., thebase station 110 a-110 d, 350) may send the pre-defined mapping as a LUTto a wireless device (e.g., the wireless device 120 a-120 e, 200, 320)in one or more Radio Resource Control (RRC) messages. As anotherexample, a base station (e.g., the base station 110 a-110 d, 350) maysend the pre-defined mapping as a LUT to a wireless device (e.g., thewireless device 120 a-120 e, 200, 320) in one or more Media AccessControl (MAC) Control Element (CE) (MAC-CE) messages.

In some embodiments, the pre-defined mapping of Re-Tx cycle numbers toprobability values may be updated (or adapted) based on one or moredynamic parameters observed by the sending device (e.g., the basestation 110 a-110 d, 350 and/or the wireless device 120 a-120 e, 200,320), such as channel response, mappings of various code blocks, etc.For example, values in a LUT in which Re-Tx cycle numbers are correlatedwith probabilities of successful decoding “p” may be updated based onone or more dynamic parameters observed by the sending device, such aschannel response, mappings of various code blocks, etc. The sendingdevice may signal the updated values per allocation in the DownlinkControl Information (DCI).

In some embodiments, the pre-defined mapping of Re-Tx cycle numbers toprobability values may be updated (or adapted) based on adaptation rulesavailable to the receiving device (e.g., the base station 110 a-110 d,350 and/or the wireless device 120 a-120 e, 200, 320) and/or sendingdevice (e.g., the base station 110 a-110 d, 350 and/or the wirelessdevice 120 a-120 e, 200, 320). The adaptation rules may govern howprobabilities of successful decoding “p” in the pre-defined mapping ofRe-Tx cycle numbers to probability values may be changed based onobserved conditions. As an example, an adaptation rule may indicate thatif a CB is observed to fall on a spur location in frequency, theprobability values for that CB may be decreased. As another example, anadaptation rule may indicate that if a CB is far from DMRSs, theprobability values for that CB may be decreased.

In some embodiments, the adaptation rules may be provided from a sendingdevice to a receiving device. In a non-limiting example, a base station(e.g., the base station 110 a-110 d, 350) may send adaptation rules to awireless device (e.g., the wireless device 120 a-120 e, 200, 320) in oneor more RRC messages. In another example, a base station (e.g., the basestation 110 a-110 d, 350) may send the adaptation rules to a wirelessdevice (e.g., the wireless device 120 a-120 e, 200, 320) in one or moreMAC-CE messages. In response to receiving adaptation rules, the sendingdevice (e.g., the base station 110 a-110 d, 350 and/or the wirelessdevice 120 a-120 e, 200, 320) may apply the adaptation rules to adjustthe probabilities of successful decoding “p” used for various CBs.

In some embodiments, combinations of both updating the pre-definedmapping of Re-Tx cycle numbers to probability values based on one ormore dynamic parameters observed by the sending device (e.g., the basestation 110 a-110 d, 350 and/or the wireless device 120 a-120 e, 200,320), such as channel response, mappings of various code blocks, etc.and updating the pre-defined mapping of Re-Tx cycle numbers toprobability values may be updated (or adapted) based adaptation rulesavailable to the receiving device (e.g., the base station 110 a-110 d,350 and/or the wireless device 120 a-120 e, 200, 320) and/or sendingdevice (e.g., the base station 110 a-110 d, 350 and/or the wirelessdevice 120 a-120 e, 200, 320) may be implemented together.

In some embodiments, a number of CBs to feedback “N” may bepre-configured by a device, such as a receiving device (e.g., the basestation 110 a-110 d, 350 and/or the wireless device 120 a-120 e, 200,320), or a sending device (e.g., the base station 110 a-110 d, 350and/or the wireless device 120 a-120 e, 200, 320), etc. In someembodiments, both the receiving device (e.g., the base station 110 a-110d, 350 and/or the wireless device 120 a-120 e, 200, 320) and the sendingdevice (e.g., the base station 110 a-110 d, 350 and/or the wirelessdevice 120 a-120 e, 200, 320) may be configured with the same number ofCBs to feedback “N”. In some embodiments, the number of CBs to feedback“N” may be determined by a sending device based on receiving deviceadvertised capabilities. For example, a receiving device may advertisethat the receiving device is lossy compression and dynamic codebookcapability enabled, and in response to the advertised capabilities thesending device may determine the number of CBs to feedback “N”. In someembodiments, the number of CBs to feedback “N” may be provided from asending device to a receiving device. In a non-limiting example, a basestation (e.g., the base station 110 a-110 d, 350) may send the number ofCBs to feedback “N” to a wireless device (e.g., the wireless device 120a-120 e, 200, 320) in one or more RRC messages. In another example, abase station (e.g., the base station 110 a-110 d, 350) may send thenumber of CBs to feedback “N” to a wireless device (e.g., the wirelessdevice 120 a-120 e, 200, 320) in one or more MAC-CE messages.

In some embodiments, a number of waveforms to be used for feedback “K”may be pre-configured by a device, such as a receiving device (e.g., thebase station 110 a-110 d, 350 and/or the wireless device 120 a-120 e,200, 320), or a sending device (e.g., the base station 110 a-110 d, 350and/or the wireless device 120 a-120 e, 200, 320), etc. In someembodiments, both the receiving device (e.g., the base station 110 a-110d, 350 and/or the wireless device 120 a-120 e, 200, 320) and the sendingdevice (e.g., the base station 110 a-110 d, 350 and/or the wirelessdevice 120 a-120 e, 200, 320) may be configured with the same number ofwaveforms to be used for feedback “K”. In some embodiments, the numberof waveforms to be used for feedback “K” may be determined by a sendingdevice based on receiving device advertised capabilities. For example, areceiving device may advertise that the receiving device is lossycompression and dynamic codebook capability enabled, and in response tothe advertised capabilities the sending device may determine the numberof waveforms to be used for feedback “K”. In some embodiments, thenumber of waveforms to be used for feedback “K” may be provided from asending device to a receiving device. In a non-limiting example, a basestation (e.g., the base station 110 a-110 d, 350) may send the number ofwaveforms to be used for feedback “K” to a wireless device (e.g., thewireless device 120 a-120 e, 200, 320) in one or more RRC messages. Inanother example, a base station (e.g., the base station 110 a-110 d,350) may send the number of waveforms to be used for feedback “K” to awireless device (e.g., the wireless device 120 a-120 e, 200, 320) in oneor more MAC-CE messages.

In various embodiments, a receiving device (e.g., the base station 110a-110 d, 350 and/or the wireless device 120 a-120 e, 200, 320) mayreceive transmissions of CBs, such as HARQ messages, for a symbol of aslot, such as a MIRS slot from a sending device (e.g., the base station110 a-110 d, 350 and/or the wireless device 120 a-120 e, 200, 320). Thesending device may send the transmissions of the CBs, such as HARQtransmissions, for the symbol of the slot, such as a MIRS slot from asending device. The receiving device receives the transmission, such asthe HARQ messages, and attempts to decode the CBs for the symbol of theslot.

A decoding attempt may include computation of logarithm likelihoodratios (LLRs) for different bit positions of the CB. The LLRs may beused to generate decoded data bits. The decoding attempt also mayinclude computation of an error checking value that can be compared witherror checking information embedded in the CB. A CB is successfullydecoded when the receiving device can verify that the computed errorchecking value matches the error checking information embedded in theCB. In some implementations, the receiving device may attempt to useerror correction to correct bit errors and compute another errorchecking value.

After a threshold number of decoding attempts, if the receiving devicecannot verify the error checking value, the receiving device maydetermine that it has failed to decode the CB. A success or failure todecode a CB may be referred to as a decoding result. Successful decodingof a CB may be associated with an acknowledgement (ACK) condition, forexample indicated by a bit value of “0” in feedback message. Failure todecode (or unsuccessful decoding of) a CB may be associated with anegative acknowledgement (NACK) condition, for example indicated by abit value of “1” in a feedback message.

The receiving device may send a feedback message, such as a HARQmessage, including an indication of the decoding results for thefeedback group, such as the decoding results for the portion of thesymbol, the decoding results for the symbol, or the decoding results forthe group of symbols. The feedback message may include a feedback bitmaprepresenting whether CBs in the feedback group, such as the portion ofthe symbol, the symbol, or the group of symbols, were successfullydecoded. For example, bit positions in the feedback bitmap of a value“0” may indicate an ACK condition representing successful decoding ofthe CB associated with that bit position and bit positions in thefeedback bitmap of a value “1” may indicate a NACK conditionrepresenting decoding failure of the CB associated with that bitposition. The sending device may receive the feedback message, such as aHARQ message, from the receiving device, and the sending message mayinitiate Re-Tx of the failed decoding CBs based on the feedback bitmapin the feedback message.

In various embodiments, a non-compressed (or uncompressed) message mayinclude feedback bitmaps for each possible combination of CB decodingoutcomes of the feedback group, such as the portion of the symbol, thesymbol, or the group of symbols. In some embodiments, a compressioncodebook may include feedback bitmaps for less than all possiblecombinations of CB decoding outcomes of the feedback group, such as theportion of the symbol, the symbol, or the group of symbols. In someembodiments, a compression codebook may be selected to generate feedbackbitmaps for less than all possible combinations of CB decoding outcomesof the feedback group, such as the portion of the symbol, the symbol, orthe group of symbols, thereby reducing an amount of feedback data sentto indicate CB decoding outcomes in comparison to non-compressed (oruncompressed) messages.

In some embodiments, a different compression codebook may be used perfeedback group, such as per portion of a symbol, per symbol, or pergroup of symbols, based at least in part on current probabilities ofsuccessful decoding “p” for the CBs in the symbol, or group of symbols.

FIG. 5 is a table illustrating example codebooks and resultingdistortions for code block feedback in accordance with variousembodiments. With reference to FIGS. 1-5 , an example of three CBs offeedback where N=3 is illustrated. Per symbol transmission, one or moreof the three CBs may either be successfully decoded as indicated by avalue “0” (e.g., an ACK condition) or decoding may fail as representedby a value “1” (e.g., a NACK condition). As such, the non-compressedfeedback message for the various states may have eight possible feedbackbitmap values “000”, “001”, “010”, “011”, “100”, “101”, “110”, and“111”. The position in the feedback bitmap may correspond to thedecoding success or failure state of an assigned CB, such as the firstposition (e.g., far left) indicating the state of the first CB, thesecond position (e.g., middle) indicating the state of the second CB,and the third position (e.g., far right) indicating the state of thethird CB. As examples, “000” in the feedback bitmap value of thenon-compressed feedback message may indicate decoding succeeded for allthree CBs, “111” in the feedback bitmap value of the non-compressedfeedback message may indicate decoding failed for all three CBs, and“101” in the feedback bitmap value of the non-compressed feedbackmessage may indicate decoding failed for the first and third CB, butsucceeded for the second CB.

In various embodiments, the number of CBs to feedback “N”, the value ofthe number of waveforms to be used for feedback “K”, and theprobabilities of successful decoding “p0 . . . pN−1” may be known toboth the sending device (e.g., the base station 110 a-110 d, 350 and/orthe wireless device 120 a-120 e, 200, 320) and the receiving device(e.g., the base station 110 a-110 d, 350 and/or the wireless device 120a-120 e, 200, 320). FIG. 5 illustrates an example in which the N=3(e.g., 3 CBs feedback), probabilities of successful decoding the firstCB and the second CB are the same at p0=p0=0.3 and the probability ofsuccessful decoding the third CB is p3=0.7. FIG. 5 also illustratesresulting codebooks A, B, C, D, E, F, and G for different K values, K=8,K=7, K=6, K=5, K=4, K=3, and K=2.

FIG. 5 illustrates the message probability of any of the non-compressedfeedback bitmaps occurring. As examples, the message probability of“000” occurring is 0.063 (e.g., 0.3×0.3.×0.7=0.063), the messageprobability of “001” is 0.027 (e.g., 0.3×0.3×0.3=0.027), the messageprobability of “010” is 0.147 (e.g., 0.3×0.7×0.7=0.147), the messageprobability of “110” is 0.343 (e.g., 0.7×0.7×0.7=0.343), and the messageprobability of “111” is 0.147 (e.g., 0.7×0.7×0.3=0.147).

In various embodiments, a compression codebook for a given number of CBsto feedback “N”, a given of the number of waveforms to be used forfeedback “K”, and given probabilities of successful decoding “p0 . . .pN−1” may be found by searching the available codebooks for acompression codebook having a lowest rate distortion measure “D”. Insome embodiments, the available codebooks may be all codebooks availableto the device. In some embodiments, the available codebooks may be agroup of allowed codebooks signaled from the sending device to thereceiving device. As examples, the group of allowed codebooks may besignaled to the receiving device by the sending device via one or moreRRC messages or one or more MAC-CE messages. In some embodiments, theavailable codebooks may be a single codebook dynamically signaled to thereceiving device by the sending device for use with a specific number ofCBs to feedback “N”, a specific number of waveforms to be used forfeedback “K”, and specific probabilities of successful decoding “p0 . .. pN−1”. As an example, the dynamically signaled codebook may beindicated to the receiving device by the sending device in overheadinformation.

FIG. 5 further illustrates example codebooks A, B, C, D, E, F, and Gselected for the corresponding K values, 8, 7, 6, 5, 4, 3, and 2.Codebook A may be an uncompressed codebook in which no distortion occursas eight bits of feedback may be sufficient to fully send thenon-compressed message. Codebooks B-G may represent compressed codebooksin which at least one of the feedback bitmaps of the non-compressedmessage is substituted with a replacement feedback bitmap. Thereplacement of the feedback bitmap with a replacement feedback bitmapmay result in compression of the feedback data as less than eight bitsmay be used for Re-Tx signaling. For example, codebook B may be acompression codebook used when K=7 and may substitute the non-compressedfeedback bitmap “001” with the replacement feedback bitmap “101” suchthat only seven bits are needed for Re-Tx signaling. Such replacement incodebook B may result in a single excess Re-Tx that contributes to therate distortion measurement “D”, which may be 0.027 for K=7. As anotherexample, codebook C may be a compression codebook used when K=6 and maysubstitute the non-compressed feedback bitmap “001” with the replacementfeedback bitmap “101” and the non-compressed feedback bitmap “011” withthe replacement feedback 111, such that only six bits are needed forRe-Tx signaling. Such replacement in codebook C may result in a twosingle excess Re-Tx that contribute to the rate distortion measurement“D”, which may be 0.09 for K=6 (e.g., 0.27+0.063=0.09). As anotherexample, codebook G may be a compression codebook used when K=2 and maysubstitute the non-compressed feedback bitmaps “000”, “010”, and “100”with the replacement feedback bitmap “110” and the feedback bitmaps“001”, “011”, and “101” with replacement feedback bitmap “111”. In thismanner, only two bits are needed for Re-Tx signaling, such that log2(2)=1 bit of feedback, e.g., “0” is signaling uncompressed “110” and“1” is signaling uncompressed “111”. Such a replacement in codebook Gmay result in four single excess Re-Tx scenarios and two double excessre-Tx scenarios that contributes to the rate distortion measurement “D”,which may be 0.6 for K=2. In the case of K=2, the single ACK (equivalentto codebook of “000” and “111”, i.e., a codebook other than codebook G)may not be suitable for K=2, though a different codebook may becomesuitable on a next Re-Tx where failure probabilities may decrease. Assuch, the compression codebook may change on the next Re-Tx cycle.

In various embodiments, a gap-to-capacity number of units may bedetermined, and/or signaled to, a sending device (e.g., the base station110 a-110 d, 350 and/or the wireless device 120 a-120 e, 200, 320). Invarious embodiments, a gap-to-capacity number of units of a certain CBmay be the size of the redundancy bits that needs to be sent in nexttransmissions to ensure decoding of that CB. Determining or signalingthe gap-to-capacity number of units may enable the sending device toadjust the size of the Re-Tx (e.g., increase the number of redundancybits used in the next Re-Tx cycle), and thereby possibly reduce thelatency due to requiring less Re-Tx. The gap-to-capacity number of unitsmay be the number of Re-Tx cycles needed to result in successfuldecoding of an ACK indicated CB in the same slot. In this manner, ratherthan incrementing the MCS a single level in the next Re-Tx cycle, thesending device may skip to the coding rate that resulted in successfuldecoding of an ACK indicated CB in the same slot. In some embodiments,in response to all CBs in a slot being NACK indicated, gap-to-capacitynumber of units may be explicitly indicated. The gap-to-capacity numberof units may be indicated once per slot for one CB, resulting in therequired overhead in transmission to indicate gap-to-capacity number ofunits being almost negligible. As an example, the last report in anallocation/slot may be used as an extended codebook where the extensionindicates the gap to capacity. As another example, the feedback bitmap“111” as illustrated in FIG. 5 may be extended to “111-1” to indicatedgap-to-capacity is one unit, “111-2” to indicate gap-to-capacity is twounits, etc., where the unit signals a lowest granularity of addingredundancy bits in the MIRS scheme.

In some embodiments, a feedback rank indication may be sent per slot orallocation. As an example, the last report in an allocation/slot may beused as an extended codebook where the extension indicates the feedbackrank. The feedback rank indication may be per slot or allocation andneed not be associated with a TB.

FIG. 6 is a process flow diagram illustrating a method 600 forsupporting lossy compression feedback in wireless communicationretransmissions in accordance with various embodiments. With referenceto FIGS. 1-6 , the method 600 may be performed by a processor (e.g.,210, 212, 214, 216, 218, 252, 260) of a sending device (e.g., the basestation 110 a-110 d, 350 and/or the wireless device 120 a-120 e, 200,320). With reference to FIGS. 1-6 , means for performing each of theoperations of the method 600 may be one or more processors of a sendingdevice (e.g., the base station 110 a-110 d, 350 and/or the wirelessdevice 120 a-120 e, 200, 320), such as one or more of the processors210, 212, 214, 216, 218, 252, 260.

In block 602, the processor may perform operations including generatinga mapping of retransmission cycle numbers to probability values. Forexample, the processor may determine probabilities of successfullydecoding “p” for various different Re-Tx cycles based at least in parton one or more factors including, the number of the re-Tx cycle, anexistence of spurs and/or notches in frequency and/or time, a proximityof a DMRS, a current estimated SNR, a current number of MIMO layers,etc. As an example, the mapping may be generated as a LUT correlatingsuccessive Re-Tx cycle numbers with respective probability values.

In block 604, the processor may perform operations including sending themapping of retransmission cycle numbers to probability values to areceiving device. As examples, the mapping may be sent in one or moremessages sent from a sending device to a receiving device, such as RRCmessages, MAC-CE messages, etc. As specific examples, the mapping may besent as a LUT to a receiving device in one or more RRC messages, in oneor more MAC-CE messages, etc.

In block 606, the processor may perform operations including determininga number of code blocks (CBs) to feedback “N”. In some embodiments, anumber of CBs to feedback “N” may be pre-configured by the processor. Insome embodiments, the number of CBs to feedback “N” may be determined bya sending device based on receiving device advertised capabilities. Forexample, a receiving device may advertise that the receiving device isenabled with lossy compression and dynamic codebook capability, and inresponse to the advertised capabilities the processor may determine thenumber of CBs to feedback “N”.

In block 608, the processor may perform operations including sending anindication of the number of code blocks (CBs) to feedback “N” to thereceiving device. As an example, the number of CBs to feedback “N” maybe sent in one or more messages sent from a sending device to areceiving device, such as RRC messages, as MAC-CE messages, etc.

In block 610, the processor may perform operations including determininga number of waveforms to be used for feedback “K”. In some embodiments,a number of waveforms to be used for feedback “K” may be pre-configuredby the processor. In some embodiments, the number of waveforms to beused for feedback “K” may be determined based on receiving deviceadvertised capabilities. For example, a receiving device may advertisethat the receiving device is enabled with lossy compression and dynamiccodebook capability, and in response to the advertised capabilities theprocessor device may determine the number of waveforms to be used forfeedback “K”.

In block 612, the processor may perform operations including sending anindication of the number of waveforms to be used for feedback “K” to thereceiving device. As an example, the number of waveforms to be used forfeedback “K” may be sent in one or more messages sent from a sendingdevice to a receiving device, such as RRC messages, as MAC-CE messages,etc.

FIG. 7 is a process flow diagram illustrating a method 700 forsupporting lossy compression feedback in wireless communicationretransmissions in accordance with various embodiments. With referenceto FIGS. 1-7 , the method 700 may be performed by a processor (e.g.,210, 212, 214, 216, 218, 252, 260) of a sending device (e.g., the basestation 110 a-110 d, 350 and/or the wireless device 120 a-120 e, 200,320). With reference to FIGS. 1-7 , means for performing each of theoperations of the method 700 may be one or more processors of a sendingdevice (e.g., the base station 110 a-110 d, 350 and/or the wirelessdevice 120 a-120 e, 200, 320), such as one or more of the processors210, 212, 214, 216, 218, 252, 260. In various embodiments, theoperations of the method 700 may be performed in conjunction with theoperations of the method 600 (FIG. 6 ).

In block 702, the processor may perform operations including determiningan update to the mapping of retransmission cycle numbers to probabilityvalues. In some embodiments, the mapping of Re-Tx cycle numbers toprobability values may be updated (or adapted) based on one or moredynamic parameters observed by the processor, such as channel response,mappings of various code blocks, etc. For example, values in a LUT inwhich Re-Tx cycle numbers are correlated with probabilities ofsuccessful decoding “p” may be updated based on the one or more dynamicparameters observed by the processor, such as channel response, mappingsof various code blocks, etc. In some embodiments, the mapping of Re-Txcycle numbers to probability values may be updated (or adapted) based onadaptation rules available to the processor. The adaptation rules maygovern how probabilities of successful decoding “p” in the pre-definedmapping of Re-Tx cycle numbers to probability values may be changedbased on observed conditions. As an example, an adaptation rule mayindicate that if a CB is observed to fall on a spur location infrequency, the probability values for that CB may be decreased. Asanother example, an adaptation rule may indicate that if a CB is farfrom DMRSs, the probability values for that CB may be decreased.

In block 704, the processor may perform operations including sending anindication of the update to the mapping of retransmission cycle numbersto probability values to the receiving device. For example, theprocessor may signal the updated values per allocation in the DCI.

FIG. 8 is a process flow diagram illustrating a method 800 forsupporting lossy compression feedback in wireless communicationretransmissions in accordance with various embodiments. With referenceto FIGS. 1-8 , the method 800 may be performed by a processor (e.g.,210, 212, 214, 216, 218, 252, 260) of a sending device (e.g., the basestation 110 a-110 d, 350 and/or the wireless device 120 a-120 e, 200,320). With reference to FIGS. 1-8 , means for performing each of theoperations of the method 800 may be one or more processors of a sendingdevice (e.g., the base station 110 a-110 d, 350 and/or the wirelessdevice 120 a-120 e, 200, 320), such as one or more of the processors210, 212, 214, 216, 218, 252, 260. In various embodiments, theoperations of the method 800 may be performed in conjunction with theoperations of the method 600 (FIG. 6 ) and/or the method 700 (FIG. 7 ).

In block 802, the processor may perform operations including determininggroup of allowed codebooks for a receiving device. The allowed codebooksmay be determined on various parameters observed and/or determined bythe processor and/or signaled by the receiving device, such as channelresponse, mappings of various code blocks, a number of CBs to feedback“N”, a number of waveforms to be used for feedback “K”, probabilities ofsuccessful decoding “p0 . . . pN−1”, etc. The allowed codebooks may be asingle codebook, two or more codebooks, etc. The allowed codebooks maybe dynamically determined by the processor.

In some embodiments, allowed codebooks may be determined based on allcodebooks available to the device. For example, the group of allowedcodebooks may be signaled to the receiving device by the sending devicevia one or more RRC messages or one or more MAC-CE messages. In someembodiments, the available codebooks may be a single codebookdynamically signaled to the receiving device by the sending device foruse with a specific number of CBs to feedback “N”, a specific number ofwaveforms to be used for feedback “K”, and specific probabilities ofsuccessful decoding “p0 . . . pN−1”. As an example, the dynamicallysignaled codebook may be indicated to the receiving device by thesending device in overhead information.

In block 804, the processor may perform operations including and sendingan indication of the group of allowed codebooks to the receiving device.For example, the indication of the group of allowed codebooks may besent in one or more messages sent from a sending device to a receivingdevice, such as RRC messages, as MAC-CE messages, etc. As anotherexample, the indication of the group of allowed codebooks may be sent inoverhead information.

FIG. 9 is a process flow diagram illustrating a method 900 forsupporting lossy compression feedback in wireless communicationretransmissions in accordance with various embodiments. With referenceto FIGS. 1-9 , the method 900 may be performed by a processor (e.g.,210, 212, 214, 216, 218, 252, 260) of a sending device (e.g., the basestation 110 a-110 d, 350 and/or the wireless device 120 a-120 e, 200,320). With reference to FIGS. 1-9 , means for performing each of theoperations of the method 900 may be one or more processors of a sendingdevice (e.g., the base station 110 a-110 d, 350 and/or the wirelessdevice 120 a-120 e, 200, 320), such as one or more of the processors210, 212, 214, 216, 218, 252, 260. In various embodiments, theoperations of the method 900 may be performed in conjunction with theoperations of the method 600 (FIG. 6 ), the method 700 (FIG. 7 ), and/orthe method 800 (FIG. 8 ).

In block 902, the processor may perform operations including receiving afeedback message from the receiving device including an indication of agap-to-capacity number of units for a next retransmission. In variousembodiments, a gap-to-capacity number of units of a certain CB may bethe size of the redundancy bits that needs to be sent in nexttransmissions to ensure decoding of that CB. The gap-to-capacity numberof units may be the number of Re-Tx cycles needed to result insuccessful decoding of an ACK indicated CB in the same slot.

In block 904, the processor may perform operations including adjusting aretransmission modulation and coding scheme for a next retransmission bythe gap-to-capacity number of units. The adjustment may includedecreasing the coding rate for a next retransmission by a value greaterthan one. For example, as the gap-to-capacity number of units may be thenumber of Re-Tx cycles needed to result in successful decoding of a NACKindicated CB in the same slot, rather than incrementing the coding ratea single level in the next Re-Tx cycle, the processor may adjust theretransmission size to skip to the coding rate that resulted insuccessful decoding of a NACK indicated CB in the same slot.

In block 906, the processor may perform operations including sending thenext retransmission to the receiving device. The next retransmission maybe sent according to the retransmission system being implemented by theprocessor, such as HARQ protocols, MIRS, etc.

FIG. 10 is a process flow diagram illustrating a method 1000 forsupporting lossy compression feedback in wireless communicationretransmissions in accordance with various embodiments. With referenceto FIGS. 1-10 , the method 1000 may be performed by a processor of areceiving device (e.g., the base station 110 a-110 d, 350 and/or thewireless device 120 a-120 e, 200, 320). With reference to FIGS. 1-10 ,means for performing each of the operations of the method 1000 may beone or more processors of a receiving device (e.g., the base station 110a-110 d, 350 and/or the wireless device 120 a-120 e, 200, 320), such asone or more of the processors 210, 212, 214, 216, 218, 252, 260. Invarious embodiments, the operations of the method 1000 may be performedin conjunction with the operations of the method 600 (FIG. 6 ), themethod 700 (FIG. 7 ), the method 800 (FIG. 8 ), and/or the method 900(FIG. 9 ).

In block 1002, the processor may perform operations including receivingan indication of a number of code blocks (CBs) to feedback “N”. As anexample, the number of CBs to feedback “N” may be received in one ormore messages received by a receiving device from a sending device, suchas RRC messages, as MAC-CE messages, etc.

In block 1004, the processor may perform operations including receivingan indication of a number of waveforms “K” to be used for feedback. Asan example, the number of waveforms to be used for feedback “K” may bereceived in one or more messages received by a receiving device from asending device, such as RRC messages, as MAC-CE messages, etc.

In block 1006, the processor may perform operations including receivinga pre-defined mapping of retransmission cycle numbers to probabilityvalues. As examples, the mapping may be received in one or more messagesreceived by a receiving device from a sending device, such as RRCmessages, as MAC-CE messages, etc. As specific examples, the mapping maybe received as a LUT from a sending device in one or more RRC messages,in one or more MAC-CE messages, etc.

In block 1008, the processor may perform operations including receivinga transmission having a number of code blocks in a feedback group from asending device. As an example, the processor may perform operationsincluding receiving a transmission having a number of code blocks in asymbol from a sending device. As an example, the processor may performoperations including receiving a transmission having a number of codeblocks in a portion of a symbol from a sending device. As anotherexample, the processor may perform operations including receiving atransmission having a number of code blocks in a group of symbols from asending device.

In block 1010, the processor may perform operations including attemptingdecoding of the transmission. A decoding attempt may include computationof logarithm likelihood ratios (LLRs) for different bit positions of aCB. The LLRs may be used to generate decoded data bits. The decodingattempt also may include computation of an error checking value that canbe compared with error checking information embedded in the CB. A CB issuccessfully decoded when the processor can verify that the computederror checking value matches the error checking information embedded inthe CB. In some implementations, the processor may attempt to use errorcorrection to correct bit errors and compute another error checkingvalue.

In block 1012, the processor may perform operations includingdetermining a decoding result for a number of code blocks (CBs) in thefeedback group. The receiving device may determine that it has failed todecode a CB if the receiving device cannot verify the error checkingvalue. A success or failure to decode a CB may be referred to as adecoding result. Successful decoding of a CB may be associated with anacknowledgement (ACK) condition, for example indicated by a bit value of“0” in feedback message. Failure to decode (or unsuccessful decoding of)a CB may be associated with a negative acknowledgement (NACK) condition,for example indicated by a bit value of “1” in a feedback message.

In block 1014, the processor may perform operations including selectinga compression codebook for use in generating a feedback message for thedecoding results based at least in part on a probability of successfuldecoding of each code block in the feedback group. In some embodiments,a compression codebook may include feedback bitmaps for less than allpossible combinations of CB decoding outcomes of the feedback group,such as the portion of the symbol, the symbol, or the group of symbols.In some embodiments, a compression codebook may be selected to generatefeedback bitmaps for less than all possible combinations of CB decodingoutcomes of the feedback group, such as the portion of the symbol, thesymbol, or the group of symbols, thereby reducing an amount of feedbackdata sent to indicate CB decoding outcomes in comparison tonon-compressed (or uncompressed) messages. In some embodiments,selecting the compression codebook for use in generating the feedbackmessage for the decoding results may be based at least in part on theprobability of successful decoding of each code block in the feedbackgroup, the number of code blocks to feedback, and the number ofwaveforms to be used for feedback. In some embodiments, a differentcompression codebook may be used per feedback group, such as per portionof a symbol, per symbol, or per group of symbols, based at least in parton current probabilities of successful decoding “p” for the CBs in thesymbol, or group of symbols.

In block 1016, the processor may perform operations including generatinga feedback message for the decoding results using the selectedcompression codebook. Generating the feedback message may includegenerating feedback in accordance to the selected codebook (whichincludes feedback messages for less than all possible combinations of CBdecoding outcomes of the feedback group). The generated feedback messagemay include an indication of the decoding results for the feedbackgroup, such as the decoding results for the portion of the symbol, thedecoding results for the symbol, or the decoding results for the groupof symbols. The feedback message may include a feedback bitmaprepresenting whether CBs in the feedback group, such as the portion ofthe symbol, the symbol, or the group of symbols, were successfullydecoded. For example, bit positions in the feedback bitmap of a value“0” may indicate an ACK condition representing successful decoding ofthe CB associated with that bit position, and bit positions in thefeedback bitmap of a value “1” may indicate a NACK conditionrepresenting decoding failure of the CB associated with that bitposition. The generated feedback message may include feedback bitmapsfor less than all possible combinations of CB decoding outcomes of thefeedback group. In some embodiments, the feedback message may include afeedback rank indication. A feedback rank indication may be sent perslot or allocation. As an example, the last report in an allocation/slotmay be used as an extended codebook where the extension indicates thefeedback rank. The feedback rank indication may be per slot orallocation and need not be associated with a TB.

In block 1018, the processor may perform operations including sendingthe feedback message to the sending device. For example, the feedbackmessage may be sent to the sending device according to theretransmission system being implemented by the processor, such as HARQprotocols, MIRS, etc.

In response to sending the feedback message the processor may performthe operations in block 1008 to receive a next transmission asdescribed. The operations of blocks 1008-1018 may be performed for thenext feedback group on a per feedback group basis to select a differentcompression codebook, generate a feedback message using the differentcompression codebook, and send the feedback message to the sendingdevice.

FIG. 11 is a process flow diagram illustrating a method 1100 forsupporting lossy compression feedback in wireless communicationretransmissions in accordance with various embodiments. With referenceto FIGS. 1-11 , the method 1100 may be performed by a processor of areceiving device (e.g., the base station 110 a-110 d, 350 and/or thewireless device 120 a-120 e, 200, 320). With reference to FIGS. 1-11 ,means for performing each of the operations of the method 1100 may beone or more processors of a receiving device (e.g., the base station 110a-110 d, 350 and/or the wireless device 120 a-120 e, 200, 320), such asone or more of the processors 210, 212, 214, 216, 218, 252, 260. Invarious embodiments, the operations of the method 1100 may be performedin conjunction with the operations of the method 600 (FIG. 6 ), themethod 700 (FIG. 7 ), the method 800 (FIG. 8 ), the method 900 (FIG. 9), and/or the method 1000 (FIG. 10 ). As a specific example, theoperations of the method 1100 may be performed in response todetermining a decoding result in block 1012 of the method 1000 (FIG. 10).

In block 1102, the processor may perform operations includingdetermining a retransmission (Re-Tx) cycle number for each code block(CB) in the feedback group. The processor may track retransmission(Re-Tx) of a previously failed CB. The number of Re-Txs that haveoccurred for a CB may correspond to the Re-Tx cycle number.

In block 1104, the processor may perform operations includingdetermining the probability of successful decoding “p” of each codeblock in the first feedback group based at least in part on each codeblock's determined retransmission cycle number. The probability of ACKor NACK per CB may be represented by a probability of successfuldecoding “p”. The probability of successful decoding “p” may representthe probability that a CB is successfully decoded. The probability ofsuccessful decoding “p” may be based at least in part on one or morefactors including, the number of re-Tx cycles of that CB, an existenceof spurs and/or notches in frequency and/or time, a proximity of a DMRS,a current estimated SNR, a current number of MIMO layers, etc. In someembodiments, the probability of successful decoding “p” of each CB inthe feedback group may be determined as a probability value correlatedwith that code block's retransmission cycle number in a pre-definedmapping of retransmission cycle numbers to probability values.

In response to determining the probability of successful decoding inblock 1104, the method 1100 may proceed perform the operations in block1014 of the method 1000 (FIG. 10 ) as described.

FIG. 12 is a process flow diagram illustrating a method 1200 forsupporting lossy compression feedback in wireless communicationretransmissions in accordance with various embodiments. With referenceto FIGS. 1-12 , the method 1200 may be performed by a processor of areceiving device (e.g., the base station 110 a-110 d, 350 and/or thewireless device 120 a-120 e, 200, 320). With reference to FIGS. 1-12 ,means for performing each of the operations of the method 1200 may beone or more processors of a receiving device (e.g., the base station 110a-110 d, 350 and/or the wireless device 120 a-120 e, 200, 320), such asone or more of the processors 210, 212, 214, 216, 218, 252, 260. Invarious embodiments, the operations of the method 1200 may be performedin conjunction with the operations of the method 600 (FIG. 6 ), themethod 700 (FIG. 7 ), the method 800 (FIG. 8 ), the method 900 (FIG. 9), the method 1000 (FIG. 10 ), and/or the method 1100 (FIG. 11 ).

In block 1202, the processor may perform operations including receivingan indication of an update to the pre-defined mapping of retransmissioncycle numbers to probability values from the sending device. Forexample, the processor may receive the update to the pre-defined mappingof retransmission cycle numbers to probability values per allocation inthe DCI. The update to the pre-defined mapping of retransmission cyclenumbers to probability values from the sending device may be updated (oradapted) based on one or more dynamic parameters observed by the sendingdevice, such as channel response, mappings of various code blocks, etc.For example, values in a LUT in which Re-Tx cycle numbers are correlatedwith probabilities of successful decoding “p” may be updated based onone or more dynamic parameters observed by the sending device. In someembodiments, the pre-defined mapping of Re-Tx cycle numbers toprobability values may be updated (or adapted) based on adaptation rulesavailable to the sending device. The adaptation rules may govern howprobabilities of successful decoding “p” in the pre-defined mapping ofRe-Tx cycle numbers to probability values may be changed based onobserved conditions.

FIG. 13 is a process flow diagram illustrating a method 1300 forsupporting lossy compression feedback in wireless communicationretransmissions in accordance with various embodiments. With referenceto FIGS. 1-13 , the method 1300 may be performed by a processor of areceiving device (e.g., the base station 110 a-110 d, 350 and/or thewireless device 120 a-120 e, 200, 320). With reference to FIGS. 1-13 ,means for performing each of the operations of the method 1300 may beone or more processors of a receiving device (e.g., the base station 110a-110 d, 350 and/or the wireless device 120 a-120 e, 200, 320), such asone or more of the processors 210, 212, 214, 216, 218, 252, 260. Invarious embodiments, the operations of the method 1300 may be performedin conjunction with the operations of the method 600 (FIG. 6 ), themethod 700 (FIG. 7 ), the method 800 (FIG. 8 ), the method 900 (FIG. 9), the method 1000 (FIG. 10 ), the method 1100 (FIG. 11 ), and/or themethod 1200 (FIG. 12 ).

In block 1302, the processor may perform operations including observinga condition of the wireless communication. As examples, observedconditions of the wireless communication may include one or more of spurlocation in frequency, CB position relative to DMRSs, channel response,and/or mappings of various code blocks.

In block 1304, the processor may perform operations including updatingprobability values of the pre-defined mapping of retransmission cyclenumbers to probability values based at least in part on an adaptationrule associated with the observed condition. In some embodiments, thepre-defined mapping of Re-Tx cycle numbers to probability values may beupdated (or adapted) based on adaptation rules available to theprocessor. The adaptation rules may govern how probabilities ofsuccessful decoding “p” in the pre-defined mapping of Re-Tx cyclenumbers to probability values may be changed based on observedconditions. As an example, an adaptation rule may indicate that if a CBis observed to fall on a spur location in frequency, the probabilityvalues for that CB may be decreased. As another example, an adaptationrule may indicate that if a CB is far from DMRSs, the probability valuesfor that CB may be decreased. In some embodiments, the adaptation rulesmay be provided by the sending device, such as in one or more RRCmessages, in one or more MAC-CE messages, etc. In response to receivingadaptation rules, the processor may apply the adaptation rules to adjustthe probabilities of successful decoding “p” used for various CBs basedat least in part on an adaptation rule associated with the observedcondition.

FIG. 14 is a process flow diagram illustrating a method 1400 forsupporting lossy compression feedback in wireless communicationretransmissions in accordance with various embodiments. With referenceto FIGS. 1-14 , the method 1400 may be performed by a processor of areceiving device (e.g., the base station 110 a-110 d, 350 and/or thewireless device 120 a-120 e, 200, 320). With reference to FIGS. 1-10 ,means for performing each of the operations of the method 1400 may beone or more processors of a receiving device (e.g., the base station 110a-110 d, 350 and/or the wireless device 120 a-120 e, 200, 320), such asone or more of the processors 210, 212, 214, 216, 218, 252, 260. Invarious embodiments, the operations of the method 1400 may be performedin conjunction with the operations of the method 600 (FIG. 6 ), themethod 700 (FIG. 7 ), the method 800 (FIG. 8 ), the method 900 (FIG. 9), the method 1000 (FIG. 10 ), the method 1100 (FIG. 11 ), the method1200 (FIG. 12 ), and/or the method 1300 (FIG. 13 ). As an example, theoperations of the method 1400 may be performed in response todetermining a decoding result in block 1016 of the method 1000 (FIG. 10).

In block 1402, the processor may perform operations includingdetermining a gap-to-capacity number of units for a next retransmission.In various embodiments, a gap-to-capacity number of units of a certainCB may be the size of the redundancy bits that needs to be sent in nexttransmissions to ensure decoding of that CB. The gap-to-capacity numberof units may be the number of Re-Tx cycles needed to result insuccessful decoding of an ACK indicated CB in the same slot.

In block 1404, the processor may perform operations including insertingan indication of the gap-to-capacity number of units for the nextretransmission in the feedback message. For example, the gap-to-capacitynumber of units for the next retransmission may be indicated as a valuein a feedback message to be sent to the sending device according to theretransmission system being implemented by the processor, such as HARQprotocols, MIRS, etc.

In response to inserting the indication of the gap-to-capacity number ofunits in block 1404, the method 1400 may perform the operations in block1018 of the method 1000 (FIG. 10 ) as described.

Various embodiments may be implemented on a variety of wireless networkdevices, an example of which is illustrated in FIG. 15 in the form of awireless network computing device 1500 functioning as a network elementof a communication network, such as a base station (e.g., base station110 a-110 d, 350, etc.). Such network computing devices may include atleast the components illustrated in FIG. 15 . With reference to FIGS.1-15 , the network computing device 1500 may typically include aprocessor 1501 coupled to volatile memory 1502 and a large capacitynonvolatile memory, such as a disk drive 1503. The network computingdevice 1500 may also include a peripheral memory access device, such asa floppy disc drive, compact disc (CD) or digital video disc (DVD) drive1506 coupled to the processor 1501. The network computing device 1500may also include network access ports 1504 (or interfaces) coupled tothe processor 1501 for establishing data connections with a network,such as the Internet and/or a local area network coupled to other systemcomputers and servers. The network computing device 1500 may include oneor more antennas 1507 for sending and receiving electromagneticradiation that may be connected to a wireless communication link. Thenetwork computing device 1500 may include additional access ports, suchas USB, Firewire, Thunderbolt, and the like for coupling to peripherals,external memory, or other devices.

Various embodiments may be implemented on a variety of wireless devices(e.g., the wireless device 120 a-120 e, 200, 320), an example of whichis illustrated in FIG. 16 in the form of a smartphone 1600. Withreference to FIGS. 1-16 , the smartphone 1600 may include a first SOC202 (e.g., a SOC-CPU) coupled to a second SOC 204 (e.g., a 5G capableSOC). The first and second SOCs 202, 204 may be coupled to internalmemory 1606, 1616, a display 1612, and to a speaker 1614. Additionally,the smartphone 1600 may include an antenna 1604 for sending andreceiving electromagnetic radiation that may be connected to a wirelessdata link and/or cellular telephone transceiver 1608 coupled to one ormore processors in the first and/or second SOCs 202, 204. Smartphones1600 typically also include menu selection buttons or rocker switches1620 for receiving user inputs.

A typical smartphone 1600 also includes a sound encoding/decoding(CODEC) circuit 1610, which digitizes sound received from a microphoneinto data packets suitable for wireless transmission and decodesreceived sound data packets to generate analog signals that are providedto the speaker to generate sound. Also, one or more of the processors inthe first and second SOCs 202, 204, wireless transceiver 1608 and CODECcircuit 1610 may include a digital signal processor (DSP) circuit (notshown separately).

The processors of the wireless network computing device 1500 and thesmart phone 1600 may be any programmable microprocessor, microcomputeror multiple processor chip or chips that can be configured by softwareinstructions (applications) to perform a variety of functions, includingthe functions of the various embodiments described below. In some mobiledevices, multiple processors may be provided, such as one processorwithin an SOC 204 dedicated to wireless communication functions and oneprocessor within an SOC 202 dedicated to running other applications.Typically, software applications may be stored in the memory 1606, 1616before they are accessed and loaded into the processor. The processorsmay include internal memory sufficient to store the application softwareinstructions.

Implementation examples are described in the following paragraphs. Whilesome of the following implementation examples are described in terms ofexample methods, further example implementations may include: theexample methods discussed in the following paragraphs implemented by awireless device (either a sending device or a receiving device)including a processor configured with processor-executable instructionsto perform operations of the methods of the following implementationexamples; the example methods discussed in the following paragraphsimplemented by a wireless device (either a sending device or a receivingdevice) including means for performing functions of the methods of thefollowing implementation examples; and the example methods discussed inthe following paragraphs may be implemented as a non-transitoryprocessor-readable storage medium having stored thereonprocessor-executable instructions configured to cause a processor of awireless device (either a sending device or a receiving device) toperform operations of the methods of the following implementationexamples.

Example 1. A method for supporting lossy compression feedback inwireless communication retransmissions performed by a processor of areceiving wireless device, including: determining first decoding resultsfor a number of code blocks in a first feedback group received from asending device; selecting a first compression codebook for use ingenerating a feedback message for the first decoding results based atleast in part on a probability of successful decoding of each code blockin the first feedback group; generating a first feedback message for thefirst decoding results using the selected first compression codebook;and sending the first feedback message to the sending device.

Example 2. The method of example 1, further including: determiningsecond decoding results for a number of code blocks in a second feedbackgroup received from the sending device; selecting a second compressioncodebook for use in generating a feedback message for the seconddecoding results based at least in part on a probability of successfuldecoding of each code block in the second feedback group; generating asecond feedback message for the second decoding results using theselected second compression codebook; and sending the second feedbackmessage to the sending device.

Example 3. The method of example 2, in which the first feedback group isa first symbol received from the sending device and the second feedbackgroup is a second symbol received from the sending device.

Example 4. The method of any of examples 1-3, further including:determining a retransmission cycle number for each code block in thefirst feedback group; and determining the probability of successfuldecoding of each code block in the first feedback group based at leastin part on each code block's determined retransmission cycle number.

Example 5. The method of example 4, in which determining the probabilityof successful decoding of each code block in the first feedback groupbased at least in part on each code block's determined retransmissioncycle number includes determining the probability of successful decodingof each code block in the first feedback group as a probability valuecorrelated with that code block's retransmission cycle number in apre-defined mapping of retransmission cycle numbers to probabilityvalues.

Example 6. The method of example 5, further including: receiving fromthe sending device: an indication of a number of code blocks tofeedback; an indication of a number of waveforms to be used forfeedback; and the pre-defined mapping of retransmission cycle numbers toprobability values, in which selecting the first compression codebookfor use in generating the feedback message for the first decodingresults based at least in part on the probability of successful decodingof each code block in the first feedback group includes selecting thefirst compression codebook for use in generating the feedback messagefor the first decoding results based at least in part on the probabilityof successful decoding of each code block in the first feedback group,the number of code blocks to feedback, and the number of waveforms to beused for feedback.

Example 7. The method of example 6, further including: receiving anindication of an update to the pre-defined mapping of retransmissioncycle numbers to probability values from the sending device.

Example 8. The method of example 6, further including: observing acondition of the wireless communication; and updating probability valuesof the pre-defined mapping of retransmission cycle numbers toprobability values based at least in part on an adaptation ruleassociated with the observed condition of the wireless communication.

Example 9. The method of any of examples 1-8, in which the firstcompression codebook is selected from a group of allowed codebooksindicated by the sending device.

Example 10. The method of any of examples 1-9, in which the firstcompression codebook is signaled to the receiving device by the sendingdevice.

Example 11. The method of any of examples 1-10, further including:determining a gap-to-capacity number of units for a next retransmission;and inserting an indication of the gap-to-capacity number of units forthe next retransmission in the first feedback message.

Example 12. The method of any of examples 1-11, in which the firstfeedback message includes a feedback rank indication.

Example 13. A method for supporting lossy compression feedback inwireless communication retransmissions performed by a processor of asending wireless device, including: generating a mapping ofretransmission cycle numbers to probability values; and sending themapping of retransmission cycle numbers to probability values to areceiving device.

Example 14. The method of any of examples 13, in which the probabilityvalues are based at least in part on a number of retransmission cyclesfor a code block.

Example 15. The method of example 14, in which the probability valuesare further based at least in part on one or more of an existence offrequency spurs, a proximity of a demodulated reference signal (DMRS), acurrent estimated signal-to-noise ratio (SNR), and a current number ofMultiple Input Multiple Output (MIMO).

Example 16. The method of any of examples 13-15, further including:determining a number of code blocks to feedback; sending an indicationof the number of code blocks to feedback to the receiving device;determining a number of waveforms to be used for feedback; and sendingan indication of the number of waveforms to be used for feedback to thereceiving device.

Example 17. The method of any of examples 13-16, further including:determining an update to the mapping of retransmission cycle numbers toprobability values; and sending an indication of the update to themapping of retransmission cycle numbers to probability values to thereceiving device.

Example 18. The method of any of examples 13-17, further including:determining a group of allowed codebooks for a receiving device; andsending an indication of the group of allowed codebooks to the receivingdevice.

Example 19. The method of any of examples 13-18, further including:receiving a feedback message from the receiving device including anindication of a gap-to-capacity number of units for a nextretransmission; adjusting a retransmission size by the gap-to-capacitynumber of units; and sending the next retransmission to the receivingdevice.

As used in this application, the terms “component,” “module,” “system,”and the like are intended to include a computer-related entity, such as,but not limited to, hardware, firmware, a combination of hardware andsoftware, software, or software in execution, which are configured toperform particular operations or functions. For example, a component maybe, but is not limited to, a process running on a processor, aprocessor, an object, an executable, a thread of execution, a program,and/or a computer. By way of illustration, both an application runningon a wireless device and the wireless device may be referred to as acomponent. One or more components may reside within a process and/orthread of execution and a component may be localized on one processor orcore and/or distributed between two or more processors or cores. Inaddition, these components may execute from various non-transitorycomputer readable media having various instructions and/or datastructures stored thereon. Components may communicate by way of localand/or remote processes, function or procedure calls, electronicsignals, data packets, memory read/writes, and other known network,computer, processor, and/or process related communication methodologies.

A number of different cellular and mobile communication services andstandards are available or contemplated in the future, all of which mayimplement and benefit from the various embodiments. Such services andstandards include, e.g., third generation partnership project (3GPP),long term evolution (LTE) systems, third generation wireless mobilecommunication technology (3G), fourth generation wireless mobilecommunication technology (4G), fifth generation wireless mobilecommunication technology (5G), global system for mobile communications(GSM), universal mobile telecommunications system (UMTS), 3GSM, generalpacket radio service (GPRS), code division multiple access (CDMA)systems (e.g., cdmaOne, CDMA1020™), enhanced data rates for GSMevolution (EDGE), advanced mobile phone system (AMPS), digital AMPS(IS-136/TDMA), evolution-data optimized (EV-DO), digital enhancedcordless telecommunications (DECT), Worldwide Interoperability forMicrowave Access (WiMAX), wireless local area network (WLAN), Wi-FiProtected Access I & II (WPA, WPA2), and integrated digital enhancednetwork (iDEN). Each of these technologies involves, for example, thetransmission and reception of voice, data, signaling, and/or contentmessages. It should be understood that any references to terminologyand/or technical details related to an individual telecommunicationstandard or technology are for illustrative purposes only, and are notintended to limit the scope of the claims to a particular communicationsystem or technology unless specifically recited in the claim language.

Various embodiments illustrated and described are provided merely asexamples to illustrate various features of the claims. However, featuresshown and described with respect to any given embodiment are notnecessarily limited to the associated embodiment and may be used orcombined with other embodiments that are shown and described. Further,the claims are not intended to be limited by any one example embodiment.For example, one or more of the operations of the methods 600, 700, 800,900, 1000, 1100, 1200, 1300, and/or 1400 may be substituted for orcombined with one or more operations of the methods 600, 700, 800, 900,1000, 1100, 1200, 1300, and/or 1400.

The foregoing method descriptions and the process flow diagrams areprovided merely as illustrative examples and are not intended to requireor imply that the operations of various embodiments must be performed inthe order presented. As will be appreciated by one of skill in the artthe order of operations in the foregoing embodiments may be performed inany order. Words such as “thereafter,” “then,” “next,” etc. are notintended to limit the order of the operations; these words are used toguide the reader through the description of the methods. Further, anyreference to claim elements in the singular, for example, using thearticles “a,” “an,” or “the” is not to be construed as limiting theelement to the singular.

Various illustrative logical blocks, modules, components, circuits, andalgorithm operations described in connection with the embodimentsdisclosed herein may be implemented as electronic hardware, computersoftware, or combinations of both. To clearly illustrate thisinterchangeability of hardware and software, various illustrativecomponents, blocks, modules, circuits, and operations have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such embodimentdecisions should not be interpreted as causing a departure from thescope of the claims.

The hardware used to implement various illustrative logics, logicalblocks, modules, and circuits described in connection with theembodiments disclosed herein may be implemented or performed with ageneral purpose processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, but, in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of receiver smart objects, e.g., acombination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration. Alternatively, some operations ormethods may be performed by circuitry that is specific to a givenfunction.

In one or more embodiments, the functions described may be implementedin hardware, software, firmware, or any combination thereof. Ifimplemented in software, the functions may be stored as one or moreinstructions or code on a non-transitory computer-readable storagemedium or non-transitory processor-readable storage medium. Theoperations of a method or algorithm disclosed herein may be embodied ina processor-executable software module or processor-executableinstructions, which may reside on a non-transitory computer-readable orprocessor-readable storage medium. Non-transitory computer-readable orprocessor-readable storage media may be any storage media that may beaccessed by a computer or a processor. By way of example but notlimitation, such non-transitory computer-readable or processor-readablestorage media may include RAM, ROM, EEPROM, FLASH memory, CD-ROM orother optical disk storage, magnetic disk storage or other magneticstorage smart objects, or any other medium that may be used to storedesired program code in the form of instructions or data structures andthat may be accessed by a computer. Disk and disc, as used herein,includes compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk, and Blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofnon-transitory computer-readable and processor-readable media.Additionally, the operations of a method or algorithm may reside as oneor any combination or set of codes and/or instructions on anon-transitory processor-readable storage medium and/orcomputer-readable storage medium, which may be incorporated into acomputer program product.

The preceding description of the disclosed embodiments is provided toenable any person skilled in the art to make or use the claims. Variousmodifications to these embodiments will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other embodiments without departing from the scope of theclaims. Thus, the present disclosure is not intended to be limited tothe embodiments shown herein but is to be accorded the widest scopeconsistent with the following claims and the principles and novelfeatures disclosed herein.

1. A method for supporting lossy compression feedback in wirelesscommunication retransmissions performed by a processor of a receivingdevice, comprising: determining first decoding results for a number ofcode blocks in a first feedback group received from a sending device;selecting a first compression codebook for use in generating a feedbackmessage for the first decoding results based at least in part on aprobability of successful decoding of each code block in the firstfeedback group; generating a first feedback message for the firstdecoding results using the selected first compression codebook; andsending the first feedback message to the sending device.
 2. The methodof claim 1, further comprising: determining second decoding results fora number of code blocks in a second feedback group received from thesending device; selecting a second compression codebook for use ingenerating a feedback message for the second decoding results based atleast in part on a probability of successful decoding of each code blockin the second feedback group; generating a second feedback message forthe second decoding results using the selected second compressioncodebook; and sending the second feedback message to the sending device.3. The method of claim 2, wherein the first feedback group is a firstsymbol received from the sending device and the second feedback group isa second symbol received from the sending device.
 4. The method of claim1, further comprising: determining a retransmission cycle number foreach code block in the first feedback group; and determining theprobability of successful decoding of each code block in the firstfeedback group based at least in part on each code block's determinedretransmission cycle number.
 5. The method of claim 4, whereindetermining the probability of successful decoding of each code block inthe first feedback group based at least in part on each code block'sdetermined retransmission cycle number comprises determining theprobability of successful decoding of each code block in the firstfeedback group as a probability value correlated with that code block'sretransmission cycle number in a pre-defined mapping of retransmissioncycle numbers to probability values.
 6. The method of claim 5, furthercomprising: receiving from the sending device: an indication of a numberof code blocks to feedback; an indication of a number of waveforms to beused for feedback; and the pre-defined mapping of retransmission cyclenumbers to probability values, wherein selecting the first compressioncodebook for use in generating the feedback message for the firstdecoding results based at least in part on the probability of successfuldecoding of each code block in the first feedback group comprisesselecting the first compression codebook for use in generating thefeedback message for the first decoding results based at least in parton the probability of successful decoding of each code block in thefirst feedback group, the number of code blocks to feedback, and thenumber of waveforms to be used for feedback.
 7. The method of claim 6,further comprising: receiving an indication of an update to thepre-defined mapping of retransmission cycle numbers to probabilityvalues from the sending device.
 8. The method of claim 6, furthercomprising: observing a condition of the wireless communication; andupdating probability values of the pre-defined mapping of retransmissioncycle numbers to probability values based at least in part on anadaptation rule associated with the observed condition of the wirelesscommunication.
 9. The method of claim 1, wherein the first compressioncodebook is selected from a group of allowed codebooks indicated by thesending device.
 10. The method of claim 1, wherein the first compressioncodebook is signaled to the receiving device by the sending device. 11.The method of claim 1, further comprising: determining a gap-to-capacitynumber of units for a next retransmission; and inserting an indicationof the gap-to-capacity number of units for the next retransmission inthe first feedback message.
 12. The method of claim 1, wherein the firstfeedback message includes a feedback rank indication. 13-19. (canceled)20. A wireless device, comprising: a processor configured to: determinefirst decoding results for a number of code blocks in a first feedbackgroup received from a sending device; select a first compressioncodebook for use in generating a feedback message for the first decodingresults based at least in part on a probability of successful decodingof each code block in the first feedback group; generate a firstfeedback message for the first decoding results using the selected firstcompression codebook; and send the first feedback message to the sendingdevice.
 21. The wireless device of claim 20, wherein the processor isfurther configured to: determine second decoding results for a number ofcode blocks in a second feedback group received from the sending device;select a second compression codebook for use in generating a feedbackmessage for the second decoding results based at least in part on aprobability of successful decoding of each code block in the secondfeedback group; generate a second feedback message for the seconddecoding results using the selected second compression codebook; andsend the second feedback message to the sending device.
 22. The wirelessdevice of claim 20, wherein the processor is further configured to:determine a retransmission cycle number for each code block in the firstfeedback group; and determine the probability of successful decoding ofeach code block in the first feedback group based at least in part oneach code block's determined retransmission cycle number.
 23. Thewireless device of claim 20, wherein the first compression codebook isselected from a group of allowed codebooks indicated by the sendingdevice.
 24. The wireless device of claim 20, wherein the processor isfurther configured to: determine a gap-to-capacity number of units for anext retransmission; and insert an indication of the gap-to-capacitynumber of units for the next retransmission in the first feedbackmessage. 25-30. (canceled)
 31. The wireless device of claim 20, whereinthe first feedback message includes a feedback rank indication.
 32. Awireless device, comprising: means for determining first decodingresults for a number of code blocks in a first feedback group receivedfrom a sending device; means for selecting a first compression codebookfor use in generating a feedback message for the first decoding resultsbased at least in part on a probability of successful decoding of eachcode block in the first feedback group; means for generating a firstfeedback message for the first decoding results using the selected firstcompression codebook; and means for sending the first feedback messageto the sending device.
 33. The wireless device of claim 32, furthercomprising: means for determining second decoding results for a numberof code blocks in a second feedback group received from the sendingdevice; means for selecting a second compression codebook for use ingenerating a feedback message for the second decoding results based atleast in part on a probability of successful decoding of each code blockin the second feedback group; means for generating a second feedbackmessage for the second decoding results using the selected secondcompression codebook; and means for sending the second feedback messageto the sending device.
 34. The wireless device of claim 32, furthercomprising: means for determining a retransmission cycle number for eachcode block in the first feedback group; and means for determining theprobability of successful decoding of each code block in the firstfeedback group based at least in part on each code block's determinedretransmission cycle number.
 35. The wireless device of claim 32,wherein the first compression codebook is selected from a group ofallowed codebooks indicated by the sending device.
 36. The wirelessdevice of claim 32, further comprising: means for determining agap-to-capacity number of units for a next retransmission; and means forinserting an indication of the gap-to-capacity number of units for thenext retransmission in the first feedback message.
 37. The wirelessdevice of claim 32, wherein the first feedback message includes afeedback rank indication.
 38. A non-transitory processor-readablestorage medium having stored thereon processor-executable instructionsto cause a processor of a wireless device to perform operationscomprising: determining first decoding results for a number of codeblocks in a first feedback group received from a sending device;selecting a first compression codebook for use in generating a feedbackmessage for the first decoding results based at least in part on aprobability of successful decoding of each code block in the firstfeedback group; generating a first feedback message for the firstdecoding results using the selected first compression codebook; andsending the first feedback message to the sending device.
 39. Thenon-transitory processor-readable storage medium of claim 38, whereinthe stored processor-executable instructions are configured to cause theprocessor of the wireless device to perform operations furthercomprising: determining second decoding results for a number of codeblocks in a second feedback group received from the sending device;selecting a second compression codebook for use in generating a feedbackmessage for the second decoding results based at least in part on aprobability of successful decoding of each code block in the secondfeedback group; generating a second feedback message for the seconddecoding results using the selected second compression codebook; andsending the second feedback message to the sending device.
 40. Thenon-transitory processor-readable storage medium of claim 38, whereinthe stored processor-executable instructions are configured to cause theprocessor of the wireless device to perform operations furthercomprising: determining a retransmission cycle number for each codeblock in the first feedback group; and determining the probability ofsuccessful decoding of each code block in the first feedback group basedat least in part on each code block's determined retransmission cyclenumber.
 41. The non-transitory processor-readable storage medium ofclaim 38, wherein the stored processor-executable instructions areconfigured to cause the processor of the wireless device to performoperations such that the first compression codebook is selected from agroup of allowed codebooks indicated by the sending device.
 42. Thenon-transitory processor-readable storage medium of claim 38, whereinthe stored processor-executable instructions are configured to cause theprocessor of the wireless device to perform operations furthercomprising: determining a gap-to-capacity number of units for a nextretransmission; and inserting an indication of the gap-to-capacitynumber of units for the next retransmission in the first feedbackmessage.
 43. The non-transitory processor-readable storage medium ofclaim 38, wherein the stored processor-executable instructions areconfigured to cause the processor of the wireless device to performoperations such that the first feedback message includes a feedback rankindication.